Contents
MOTORCYCLE SAFETY ..............................1
Important Safety Information .............................2
Important Safety Precautions .......................2
Loading ...............................................................3
Accessories & Modifications ..............................4
Safety Labels .......................................................5
OPERATING CONTROLS .............................7
Operation Component Locations ........................8
BEFORE RIDING ............................................9
Are You Ready to Ride? ...................................10
Is Your Motorcycle Ready to Ride? ..................11
Pre-ride Inspection ......................................11
BASIC OPERATING INSTRUCTIONS ......13
Safe Riding Precautions .............................14
Starting & Stopping the Engine ........................15
Preparation .................................................. 15
Fuel Valve ...................................................15
Starting Procedure ......................................15
Flooded Engine ...........................................16
How to Stop the Engine ..............................16
Shifting Gears ...................................................17
Braking ..............................................................18
Parking ..............................................................19
Post-ride Inspection ..........................................20
Break-in Guidelines ..........................................21
SERVICING YOUR HONDA ........................23
Before You Service Your Honda
The Importance of Maintenance .......................24
Maintenance Safety ...........................................25
Important Safety Precautions .....................25
Maintenance Schedule ......................................26
General Competition Maintenance ...................29
Before & After Competition Maintenance .......33
Between Motos & Practice Maintenance ...33
After Competition Maintenance .................33
Service Preparations
Maintenance Component Locations .................35
Seat ....................................................................36
Fuel Tank ..........................................................37
Subframe Upright Position ...............................39
Service Procedures
Fluids & Filters
Fuel System .......................................................41
Engine Oil .........................................................43
Transmission Oil ...............................................46
Coolant .............................................................. 48
Air Cleaner ........................................................51
Crankcase Breather ...........................................53
Engine
Throttle ..............................................................54
Clutch System ...................................................56
Hot Start Lever ..................................................60
Spark Plug .........................................................61
Exhaust Pipe/Muffler ........................................62
Spark Arrester ...................................................65
Valve Clearance ................................................66
Piston/Piston Rings/Piston Pin .........................76
Chassis
Suspension ........................................................84
Brakes ...............................................................88
Wheels ...............................................................92
Tires & Tubes ....................................................93
Side Stand .........................................................95
Drive Chain .......................................................96
Steering Damper ...............................................99
Additional Maintenance Procedures ...............102
Electrical
Battery .............................................................104
Headlight & Taillight ......................................106
Appearance Care .............................................108
ADJUSTMENTS FOR COMPETITION ...111
Front Suspension Adjustments .......................112
Rear Suspension Adjustments .........................126
Suspension Adjustments for Track
Conditions ....................................................... 130
Suspension Adjustment Guidelines ................131
Carburetor Adjustment & Tuning Tips ...........134
Steering Damper Adjustment ..........................141
Steering Damper Adjustment Guidelines .......142
Chassis Adjustments .......................................143
Gearing ............................................................144
Tire Selection for Track Conditions ...............145
Personal Fit Adjustments ................................146
TIPS ................................................................147
Transporting Your Motorcycle ........................148
Storing Your Honda ........................................149
You & the Environment ..................................151
Troubleshooting ..............................................152
TAKING CARE OF THE UNEXPECTED
...153
If a Fuse Blows ...............................................154
If Your Battery Is Low (or Dead)....................155
TECHNICAL INFORMATION ..................157
Vehicle Identification ......................................158
Specifications ..................................................159
Torque Specifications ......................................160
Emission Control Systems ..............................164
Oxygenated Fuels ...........................................166
Competition Logbook .....................................167
Optional Parts List ..........................................169
Spare Parts & Equipment................................170
Wiring Diagram ..............................................171
CONSUMER INFORMATION ...................173
Authorized Manuals ........................................174
Warranty Coverage .........................................175
Warranty Service .............................................176
Contacting Honda ...........................................177
Your Honda Dealer .........................................178
The Honda Rider’s Club (USA only) .............179
INDEX ............................................................180
QUICK REFERENCE
Contents
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MOM 15895 (1605)
CRF450X
31MEY710
2017
Honda CRF450X
OWNER’S MANUAL & COMPETITION HANDBOOK
FOR OFF-ROAD USE ONLY
This vehicle is designed and manufactured for off-road use only.
USA only:
It conforms to US EPA Noise Emission regulations, but does not conform to Federal Motor Vehicle Safety Standards or US EPA On
Highway Exhaust Emission regulations, and operation on public streets, roads, or highways is illegal. The vehicle is equipped with a
USDA qualified spark arrester. Obey local laws and regulations.
It conforms to US EPA, California, and Environment Canada emission regulations for off-road motorcycles.
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Introduction
Introduction
Congratulations on choosing your Honda CRF
off-road motorcycle.
When you own a Honda, you’re part of a
worldwide family of satisfied customers–people
who appreciate Honda’s reputation for building
quality into every product.
Your Honda was designed as a recreational
motorcycle for off-road use by one rider only.
Before riding, take time to get acquainted with
your CRF and how it works. To protect your
investment, we urge you to take responsibility for
keeping your CRF well maintained. Scheduled
service is a must, of course. But it’s just as
important to observe the break-in guidelines, and
perform all the pre-ride and other periodic checks
detailed in this manual.
You should also read the owner’s manual before
you ride. It’s full of facts, instructions, safety
information, and helpful tips. To make it easy
to use, the manual contains a table of contents,
a detailed list of topics at the beginning of each
section, and an index at the back of the book.
As you read this manual, you will find
information that is preceded by a
NOTICE
symbol. This information is intended to help you
avoid damage to your Honda, other property, or
the environment.
Unless you are mechanically qualified and have
the proper tools, you should see your dealer for
the service and adjustment procedures discussed
in this manual.
The official Honda Service Manual for your CRF
is available (page 174). It is the same manual
your dealer uses. If you plan to do any service
on your CRF beyond the standard maintenance
procedures in this manual, you will find the
Service Manual a valuable reference.
Read the Warranties Booklet (page 175)
thoroughly so you understand the coverages that
protect your new Honda and are aware of your
rights and responsibilities.
This motorcycle has no cooling fan. For this
reason, engine overheating and coolant loss will
occur if the engine is kept idling too long when
hot. Additionally, when riding in mud or sand,
or any condition that causes high engine load at
low vehicle speed, the time it takes for the engine
to overheat will be shortened, especially when
the ambient temperature is high. Continuing to
operate the unit in these conditions will result in
engine damage.
Whenever you ride, tread lightly. By staying on
established trails and riding only in approved
areas, you help protect the environment and keep
off-road riding areas open for the future.
If you have any questions, or if you ever need
a special service or repairs, remember that your
Honda dealer knows your CRF best and is
dedicated to your complete satisfaction.
Please report any change of address or ownership
to your dealer so we will be able to contact you
concerning important product information.
You may also want to visit our website at
USA: www.powersports.honda.com.
Canada: www.honda.ca.
Happy riding!
California Proposition 65 Warning
WARNING: This product contains or emits
chemicals known to the State of California
to cause cancer and birth defects or other
reproductive harm.
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Introduction
A Few Words About Safety
Your safety, and the safety of others, is very important. And operating this motorcycle safely is an important responsibility.
To help you make informed decisions about safety, we have provided operating procedures and other information on labels and in this manual.
This information alerts you to potential hazards that could hurt you or others.
Of course, it is not practical or possible to warn you about all hazards associated with operating or maintaining a motorcycle. You must use your own good
judgment.
You will find important safety information in a variety of forms, including:
• Safety Labels –– on the motorcycle.
• Safety Messages –– preceded by a safety alert symbol
and one of three signal words: DANGER, WARNING, or CAUTION.
These signal words mean:
DANGER You WILL be KILLED or SERIOUSLY HURT if you don’t follow instructions.
WARNING
You CAN be KILLED or SERIOUSLY HURT if you don’t follow instructions.
CAUTION
You CAN be HURT if you don’t follow instructions.
• Safety Headings –– such as Important Safety Reminders or Important Safety Precautions.
• Safety Section –– such as Motorcycle Safety.
• Instructions –– how to use this motorcycle correctly and safety.
This entire book is filled with important safety information–– please read it carefully.
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Motorcycle Safety 1
Motorcycle Safety
Important Safety Information ..............................2
Important Safety Precautions .........................2
Loading ................................................................3
Accessories & Modifications ...............................4
Safety Labels ........................................................5
This section presents some of the most important
information and recommendations to help you
ride your CRF safely. Please take a few moments
to read these pages. This section also includes
information about the location of safety labels on
your CRF.
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2 Motorcycle Safety
Important Safety Information
Important Safety Precautions
Your CRF can provide many years of pleasure,
if you take responsibility for your own safety
and understand the challenges you can meet in
competitive racing.
There is much that you can do to protect
yourself when you ride. You’ll find many helpful
recommendations throughout this manual. The
following are a few that we consider to be most
important.
Always Wear a Helmet. It’s a proven fact:
helmets significantly reduce the number and
severity of head injuries. So always wear
an approved motorcycle helmet. We also
recommended that you wear eye protection,
sturdy boots, gloves, and other protective gear.
Never Carry a Passenger. Your CRF is designed
for one person only. There are no handholds,
footrests, or seat for a second person–so never
carry a passenger. A passenger could interfere
with your ability to move around to maintain
your balance and control of the motorcycle.
Ride Off-road Only. Your CRF is designed and
manufactured for off-road use only. The tires are
not made for pavement, and the CRF does not
have turn signals and other features required for
use on public roads. If you need to cross a paved
or public road, get off and walk your CRF across.
Always Wear Protective Gear. We recommend
that you wear sturdy boots, gloves, and other
protective gear. The exhaust system becomes
very hot during operation, and it remains hot
after operation. Never touch any part of the hot
exhaust system. Wear clothing that fully covers
your legs.
Keep Your Honda in Safe Condition. It’s
important to keep your CRF properly maintained
and in safe riding condition. Having a breakdown
can be difficult, especially if you are stranded
off-road far from your base. To help avoid
problems, inspect your CRF before every ride
and perform all recommended maintenance.
Do not wear loose clothing which could catch
on the control levers, kickstarter, footpegs, drive
chain, or wheels.
Take Time to Learn and Practice. Developing
off-road riding skills is a gradual, step-by-step
process. Start by practicing at low speeds in a
safe area and slowly build your skills.
Personal instruction from an experienced rider
can also be valuable.
If you need assistance, ask your dealer about
riding groups in your area.
Also be sure to read the Tips & Practice Guide
for the Off-Highway Motorcyclist booklet that
came with your CRF (USA only).
Be Alert for Off-road Hazards. The terrain can
present a variety of challenges when you ride
off-road. Continually ‘‘read” the terrain for
unexpected turns, drop-offs, rocks, ruts, and other
hazards. Always keep your speed low enough to
allow time to see and react to hazards.
Ride within Your Limits. Pushing limits is
another major cause of motorcycle crashes. Never
ride beyond your personal abilities or faster than
conditions warrant. Remember that alcohol,
drugs, fatigue, and inattention can significantly
reduce your ability to make good judgments and
ride safely.
Don’t Drink and Ride. Alcohol and riding don’t
mix. Even one drink can reduce your ability
to respond to changing conditions, and your
reaction time gets worse with every additional
drink. So don’t drink and ride, and don’t let your
friends drink and ride either.
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Motorcycle Safety 3
Loading
Your CRF was designed as a rider-only
motorcycle. It was not designed to carry a
passenger or cargo. A passenger or cargo could
interfere with your ability to move around to
maintain your balance and control of the CRF.
In addition, exceeding the weight limits or
carrying an unbalanced load can seriously affect
your CRF’s handling, braking, and stability.
Adding accessories or making modifications
that change this CRF’s design and performance
can also make it unsafe. Also, the weight of any
accessories will reduce the maximum load the
motorcycle can carry.
More specific information on load limits,
accessories, and modifications follows.
Loading
How much weight you put on your CRF, and
how you load it, are important to your safety. If
you decide to carry cargo, you should be aware
of the following information.
Loading Guidelines
As discussed on this page, we recommended that
you do not carry any cargo on this motorcycle.
However, if you decide to carry cargo, ride at
reduced speeds and follow these commonsense
guidelines:
• Keep cargo small and light. Make sure it
cannot easily be caught on brush or other
objects, and that it does not interfere with
your ability to shift position to maintain
balance and stability.
• Place weight as close to the center of the
motorcycle as possible.
• Do not attach large or heavy items (such as a
sleeping bag or tent) to the handlebar, fork, or
front fender.
• Check that both tires are inflated properly.
Overloading or carrying a passenger can
cause a crash and you can be seriously
hurt or killed.
Follow all loading guidelines in this
manual.
WARNING
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4 Motorcycle Safety
Accessories & Modifications
Accessories
We strongly recommend that you use only Honda
Genuine Accessories that have been specifically
designed or approved and tested for your CRF.
Because Honda cannot test all other accessories,
you must be personally responsible for proper
selection, installation, and use of non-Honda
accessories. Check with your dealer for
assistance and always follow this guideline:
• Make sure the accessory does not reduce
ground clearance and lean angle, limit
suspension travel or steering travel, alter your
riding position, or interfere with operating any
controls.
Modifications
We strongly advise you not to remove any
original equipment or modify your CRF in any
way that would change its design or operation.
Such changes could seriously impair your CRF’s
handling, stability, and braking, making it unsafe
to ride.
We also advise you not to make any
modifications or remove any equipment (such as
the USDA qualified spark arrester or emission
control system components) that would make the
motorcycle illegal in your area.
Accessories & Modifications
Modifying your CRF or using non-Honda
accessories can make your CRF unsafe.
Before you consider making any modifications
or adding an accessory, be sure to read the
following information.
Improper accessories or modi cations
can cause a crash in which you can be
seriously hurt or killed.
Follow all instructions in this owner’s
manual regarding modi cations and
accessories.
WARNING
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Motorcycle Safety 5
Safety Labels
This page shows the locations of safety labels on your CRF. Some labels warn you of potential hazards that could cause serious injury. Others provide
important safety information. Read these labels carefully and don’t remove them.
If the label comes off or becomes hard to read, contact your dealer for replacement.
(For Canada)
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6 Motorcycle Safety
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Blank page
8 Operating Controls
Operation Component Locations
choke knob
fuel valve
shift lever
kickstarter
rear brake pedal
clutch lever
hot start lever
front brake lever
engine stop button
throttle grip
tripmeter
start button
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Before Riding 9
Before each ride, you need to make sure you
and your Honda are both ready to ride. To help
get you prepared, this section discusses how to
evaluate your riding readiness, and what items
you should check on your CRF.
For information about suspension, carburetor, and
other adjustments see page 111.
Before Riding
Are You Ready to Ride? .................................... 10
Is Your Motorcycle Ready to Ride? ................... 11
Pre-ride Inspection .......................................11
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10 Before Riding
Are You Ready to Ride?
Before riding your CRF for the first time, we
recommend that you read this owner’s manual,
make sure you understand the safety messages,
and know how to operate the controls.
Before each ride, it’s also important to make sure
you and your CRF are both ready to ride.
For information about suspension, carburetor, and
other adjustments, see page 111.
Whether you’re preparing for competition or for
practice, always make sure you are:
• In good physical and mental condition
• Free of alcohol and drugs
• Wearing an approved helmet, eye protection,
and other appropriate riding gear
Although complete protection is not possible,
wearing the proper gear can reduce the chance or
severity of injury when you ride.
Not wearing a helmet increases the
chance of serious injury or death in a
crash.
Be sure you always wear a helmet, eye
protection and other protective apparel
when you ride.
WARNING
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Before Riding 11
Is Your Motorcycle Ready to Ride?
Competitive riding can be tough on a motorcycle,
so it’s important to inspect your CRF and correct
any problems you find before each ride. Check
the following items (page numbers are at the
right):
Pre-ride Inspection
Check the following before each ride:
• Engine oil level ............................................. 44
• Transmission oil level ...................................47
• Coolant for proper level ............................... 48
• Cooling system and hoses for condition ......49
• Spark plug for proper heat range, carbon
fouling and spark plug wire terminal for
looseness .......................................................61
• Air cleaner for condition and
contamination ...............................................51
• Clutch operation and freeplay ......................56
• Hot start lever freeplay .................................60
• Breather drain for cleaning ...........................53
• Steering head bearings and related parts
for condition ...............................................102
• Carburetor throttle operation ........................ 55
• Engine idle speed for stable and proper
rpm ..............................................................140
• Tires for damage or improper inflation
pressure ........................................................93
• Spokes for looseness .................................... 92
• Rim locks for looseness ...............................92
• Front and rear suspension for proper
operation .................................................84, 85
• Front and rear brakes, check operation ........88
• Drive chain for correct slack and
adequate lubrication ...............................96, 98
• Drive chain sliders and drive chain rollers
for damage or wear .......................................98
• Exhaust pipe/Muffler inspection ..................62
• Steering damper operation inspection ..........99
• Every possible part for looseness (such as
cylinder head nuts, engine mounting bolts/
nuts, axle nuts, handlebar holder bolts, fork
bridge pinch bolts, drive chain adjuster,
drive chain guide, wire harness connectors,
kickstarter mounting bolt, etc.) ........160 – 163
Improperly maintaining this motorcycle or
failing to correct a problem before riding
can cause a crash in which you can be
seriously hurt or killed.
Always perform a pre-ride inspection
before every ride and correct any
problems.
WARNING
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12 Before Riding
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Blank page
Basic Operating Instructions 13
Basic Operating Instructions
This section gives basic information on how to
start and stop your engine as well as break-in
guidelines.
Safe Riding Precautions ...............................14
Side Stand .....................................................14
Tripmeter ......................................................14
Starting & Stopping the Engine .........................15
Preparation ....................................................15
Fuel Valve .....................................................15
Starting Procedure ........................................15
Flooded Engine .............................................16
How to Stop the Engine ............................... 16
Shifting Gears ....................................................17
Braking ...............................................................18
Parking ...............................................................19
Post-ride Inspection ...........................................20
Break-in Guidelines ...........................................21
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14 Basic Operating Instructions
Tripmeter
The tripmeter (1) is used to record the distance
traveled (USA: miles, Canada: kilometers) per
trip or section of route.
To operate, pull the tripmeter reset knob (2) out
(OFF) and turn it until the meter shows all zeros
(0), then push the knob in (ON).
OFF
ON
(1)
(2)
(1) tripmeter
(2) tripmeter reset knob
Basic Operating Instructions
Safe Riding Precautions
Before riding your CRF for the first time,
please review the Important Safety Precautions
beginning on page 2 and the previous section,
titled Before Riding.
For your safety, avoid starting or operating the
engine in an enclosed area such as a garage.
Your CRF’s exhaust contains poisonous carbon
monoxide gas which can collect rapidly in an
enclosed area and cause illness or death.
Running the engine of your vehicle while
in an enclosed or even partially enclosed
area can cause a rapid build-up of toxic
carbon monoxide gas.
Breathing this colorless, odorless gas can
quickly cause unconsciousness and lead
to death.
Only run your vehicle's engine when it is
located in a well ventilated area outdoors.
WARNING
Side Stand
The side stand (1) is used to support your CRF
while parked (page 19). To operate, use your foot
to lower the side stand until it is fully extended.
Before riding, raise the side stand.
(1)
(1) side stand
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Basic Operating Instructions 15
Starting & Stopping the Engine
Always follow the proper starting procedure
described below.
Your CRF can be started with the transmission
in gear by pulling in the clutch lever before
operating the kickstarter or start button.
Preparation
Make sure that the transmission is in neutral.
Fuel Valve
ON OFF RES
(1)
(1) fuel valve
The three-way fuel valve is used to control the
flow of fuel from the fuel tank to the carburetor.
ON–Turning the fuel valve ON before attempting
to start the engine allows fuel to flow from the
fuel tank to the carburetor.
OFF–Turning the fuel valve OFF prevents the
flow of fuel from the fuel tank to the carburetor.
RES–Turning the fuel valve to RES allows
fuel to flow from the reserve fuel supply to the
carburetor.
Starting Procedure
Always follow the proper starting procedure
described as follow.
(1)
(2)
ON
OFF
(1) fuel valve (2) choke knob
Check the engine oil, transmission oil and
coolant levels before starting the engine (pages
44, 47, 48).
To restart a warm engine, follow the procedure
for ‘‘High Air Temperature.”
Normal Air Temperature 10°C – 35°C (50°F – 95°F)
1. Turn the fuel valve (1) ON.
2. Pull the choke knob (2) fully ON, if the
engine is cold.
3. Keep the throttle fully closed.
4. Pull the clutch lever all the way in, and depress
the start button. Or operate the kickstarter
to start the engine. Starting from the top of
the stroke, kick through to the bottom with a
rapid, continuous motion. Do not operate the
throttle.
NOTICE
Allowing the kickstarter to snap back freely
against the pedal stop can damage the engine
case.
5. Warm up the engine; don’t operate the
throttle.
6. About 15 seconds after the engine starts, push
the choke knob back all the way to fully OFF.
If idling is unstable, open the throttle slightly.
NOTICE
Extended use of the choke may impair piston and
cylinder wall lubrication and damage the engine.
High Air Temperature 35°C (95°F) or above
1. Turn the fuel valve ON.
2. Do not use the choke.
3. Keep the throttle fully closed.
4. Start the engine following step 4 under
“Normal Air Temperature.”
Low Air Temperature 10°C (50°F) or below
1. If the temperature is below 0°C (32°F), open
the throttle two or three times. (The engine
requires a richer mixture for starting in cold
weather. When the throttle is so opened, the
accelerator pump will feed extra fuel to the
cylinder, thereby facilitating starting in cold
weather.)
2. Follow steps 1 – 4 under “Normal Air
Temperature.”
3. Continue warming up the engine until it runs
smoothly and responds to the throttle when
the choke knob is pushed back all the way to
fully OFF.
NOTICE
Extended use of the choke may impair piston and
cylinder wall lubrication and damage the engine.
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16 Basic Operating Instructions
Starting & Stopping the Engine
Flooded Engine
Starting the engine after a stall during riding or
after a fall:
1. Shift the transmission into neutral.
2. Pull the hot start lever all the way in and start
the engine. (Do not open the throttle.)
3. As soon as the engine starts, release the hot
start lever.
Starting a flooded engine:
(Using the start button)
1. Do not use the choke.
2. Shift the transmission into neutral with the
throttle fully opened.
3. Pull the clutch and hot start levers all the
way in and depress the start button for 5
seconds. If the engine starts, quickly close
the throttle, then open it slightly if idling is
unstable. If the engine does not start, wait 10
seconds, and then follow the regular starting
procedure.
4. As soon as the engine starts, release the hot
start lever.
(Using the kickstarter)
1. Do not use the choke.
2. Shift the transmission into neutral with
the throttle fully opened, repeat kickstarter
operation approximately ten times very
slowly to discharge excessive fuel from the
engine. Close the throttle.
3. Pull the hot start lever all the way in and start
the engine. (Do not open the throttle.)
4. As soon as the engine starts, release the hot
start lever.
How to Stop the Engine
(1)
(2)
(1) throttle
(2) engine stop but
ton
Normal Engine Stop
1. Shift the transmission into neutral.
2. Turn the fuel valve OFF.
3. Lightly open the throttle (1) two or three
times, and then close it.
4. Push the engine stop button (2) until the
engine stops completely.
Failure to close the fuel valve may cause the
carburetor to overflow, result in hard starting.
Emergency Engine Stop
To stop the engine in an emergency, push the
engine stop button.
Hot Engine Starting
1. Pull the hot start lever (3) all the way in
and start the engine following step 4 under
“Normal Air Temperature.”
2. As soon as the engine starts, release the hot
start lever.
(3)
(3) hot start lever
Snapping the throttle or fast idling for more than
5 minutes may cause exhaust pipe discoloration.
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Basic Operating Instructions 17
Your CRF has five forward gears in a one-down,
four-up shift pattern.
To start riding, after the engine has been warmed
and the side stand raised.
1. Close the throttle and pull the brake lever in.
2. Pull the clutch lever all the way in.
3. Depress the shift lever from neutral down to
first gear.
4. Release the brake lever. Gradually open the
throttle while you slowly release the clutch
lever. If the engine rpm (speed) is too low
when you release the clutch lever, the engine
will stall.
If the engine rpm (speed) is too high or you
release the clutch lever too quickly, your CRF
may lurch forward.
5. When you attain a moderate speed, close the
throttle, pull the clutch lever in, and raise the
shift lever. After shifting, release the clutch
lever and apply the throttle.
6. To continue shifting up to each higher gear,
repeat step 5.
7. To shift down to a lower gear, close the
throttle, pull the clutch lever in, and depress
the shift lever. After shifting, release the
clutch lever and apply the throttle.
Shifting Gears
Remember to close the throttle and pull the
clutch lever in completely before shifting.
NOTICE
Improper shifting may damage the engine,
transmission, and drive train.
Learning when to shift gears comes with
experience. Upshift to a higher gear or reduce
throttle before engine rpm (speed) gets too high.
Downshift to a lower gear before you feel the
engine laboring (lugging) at low rpm.
NOTICE
Downshifting can help slow your motorcycle,
especially on downhills. However, downshifting
when engine rpm is too high can cause engine
damage.
NOTICE
To prevent transmission damage, do not coast or
tow the motorcycle for long distances with the
engine off.
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18 Basic Operating Instructions
Braking
To slow or stop, apply the front brake lever and
rear brake pedal smoothly, while downshifting
to match your speed. Gradually increase braking
as you feel the brakes slowing your speed. To
prevent stalling the engine, pull the clutch lever
in before coming to a complete stop. For support,
put your left foot down first, then your right foot
when you are through using the rear brake pedal.
For maximum braking, close the throttle and
firmly apply the front brake lever and rear brake
pedal controls.
Applying the brakes too hard may cause the
wheels to lock and slide, reducing control of your
CRF. If this happens, release the brake controls,
steer straight ahead until you regain control, then
reapply the brakes more gently.
Generally, reduce your speed or complete braking
before beginning a turn. Avoid braking or closing
the throttle quickly while turning. Either action
may cause one or both wheels to slip. Any wheel
slip will reduce your control of your CRF.
When riding in wet or raining conditions, or
on loose surfaces, the ability to maneuver
and stop will be reduced. All of your actions
should be smooth under these conditions. Rapid
acceleration, braking, or turning may cause loss
of control. For your safety, exercise extreme
caution when braking, accelerating, or turning.
When descending a long, steep grade, use engine
compression braking by downshifting, with
intermittent use of both brakes.
When you brake to a stop, pull the clutch lever
in before stopping completely to prevent stalling
the engine. For support, put your left foot on the
ground first, then your right foot when you have
finished braking.
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Basic Operating Instructions 19
Parking
Lower the side stand to support your CRF.
If you’re through riding for the day, turn the fuel
valve OFF. Always choose a level surface to park.
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20 Basic Operating Instructions
Post-ride Inspection
When you return home after riding, thoroughly
clean your CRF and remove any dirt, mud, brush,
rocks or other objects you may have picked up
along the way.
After cleaning, carefully inspect your CRF for
leaks or damage.
Be sure to lubricate the drive chain (page 98) to
prevent rusting.
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Basic Operating Instructions 21
Break-in Guidelines
Help assure your CRF’s future reliability and
performance by paying extra attention to how
you ride during the first operating day or 15
miles (25 km).
During this period, avoid full-throttle starts and
rapid acceleration.
This same procedure should be followed each
time when:
• piston is replaced
• piston rings are replaced
• cylinder is replaced
• crankshaft or crank bearings are replaced
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22 Basic Operating Instructions
17CRF450X31MEY710.indb22 2016/06/0811:45:34
Blank page
Servicing Your Honda 23
Servicing Your Honda
Keeping your CRF well maintained is absolutely
essential to your safety. It’s also a good way
to protect your investment, get maximum
performance, avoid breakdowns, and have more
fun.
To help keep your CRF in good shape, this
section includes a Maintenance Schedule for
required servicing and step-by-step instructions
for specific maintenance tasks. You’ll also find
important safety precautions, information on oils,
and tips for keeping your Honda looking good.
An ICM (Ignition Control Module) system is
used on this motorcycle; consequently, routine
ignition timing adjustment is unnecessary. If you
want to check the ignition timing, refer to the
Honda Service Manual (page 174).
For information about the exhaust emission and
noise emission requirements of the U.S.
Environmental Protection Agency (EPA), the
California Air Resources Board (CARB), and
Environment Canada (EC), see page 164.
USA only
Maintenance, replacement or repair of the
emission control devices and systems may
be performed by any motorcycle repair
establishment or individual using parts that
are ‘‘certified” to EPA standards.
An optional tool kit may be available. Check
with your dealer’s parts department.
Before You Service Your Honda
The Importance of Maintenance ........................24
Maintenance Safety ............................................25
Important Safety Precautions .......................25
Maintenance Schedule .......................................26
General Competition Maintenance ....................29
Before & After Competition Maintenance ........33
Between Motos & Practice Maintenance .....33
After Competition Maintenance ...................33
Service Preparations
Maintenance Component Locations ..................35
Seat .....................................................................36
Fuel Tank ...........................................................37
Subframe Upright Position ................................39
Service Procedures
Fluids & Filters
Fuel System ........................................................41
Engine Oil ..........................................................43
Transmission Oil ................................................46
Coolant ............................................................... 48
Air Cleaner .........................................................51
Crankcase Breather ............................................53
Engine
Throttle ...............................................................54
Clutch System ....................................................56
Hot Start Lever ................................................... 60
Spark Plug ..........................................................61
Exhaust Pipe/Muffler .........................................62
Spark Arrester ....................................................65
Valve Clearance .................................................66
Piston/Piston Rings/Piston Pin ..........................76
Chassis
Suspension .........................................................84
Front Suspension Inspection ........................84
Rear Suspension Inspection .........................85
Recommended Fork Oil ...............................86
Fork Oil Change ...........................................86
Brakes ................................................................88
Wheels ................................................................92
Tires & Tubes .....................................................93
Side Stand ..........................................................95
Drive Chain ........................................................96
Steering Damper ................................................99
Additional Maintenance Procedures ................102
Electrical
Battery ..............................................................104
Headlight & Taillight ....................................... 106
Appearance Care ..............................................108
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24 Servicing Your Honda
Improperly maintaining this motorcycle
or failing to correct a problem before you
ride can cause a crash in which you can
be seriously hurt or killed.
Always follow the inspection and
maintenance recommendations and
schedules in this owner’s manual.
WARNING
The Importance of Maintenance
A well-maintained motorcycle is essential for
safe, economical, and trouble-free riding. It will
also help reduce air pollution. Careful pre-ride
inspections and good maintenance are especially
important because your CRF is designed to be
ridden over rough off-road terrain.
To help you properly care for your CRF, this
section of the manual provides a Maintenance
Schedule. The service intervals in this schedule
are based on average riding conditions.
More frequent service is needed if you subject
your CRF to severe use or ride in unusually wet
or dusty areas.
Frequent servicing of the air cleaner is especially
important to help you avoid a possible costly
engine repair.
If your CRF overturns or is involved in a crash,
be sure your dealer inspects all major parts, even
if you are able to make some repairs.
Remember, proper maintenance is your
responsibility. Be sure to inspect your CRF
before each ride and follow the Maintenance
Schedule in this section.
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Servicing Your Honda 25
Maintenance Safety
This section includes instructions on how to
perform some important maintenance tasks.
Some of the most important safety precautions
follow. However, we cannot warn you of every
conceivable hazard that can arise in performing
maintenance. Only you can decide whether or not
you should perform a given task.
Failure to properly follow maintenance
instructions and precautions can cause
you to be seriously hurt or killed.
Always follow the procedures and
precautions in this owner’s manual.
WARNING
Important Safety Precautions
• Make sure the engine is off before you begin
any maintenance or repairs.
This will help eliminate several potential
hazards:
Carbon monoxide poisoning from engine
exhaust. Be sure there is adequate ventilation
whenever you operate the engine.
Burns from hot motorcycle parts. Let
the engine and exhaust system cool before
touching.
Injury from moving parts. Do not run the
engine unless instructed to do so.
• Read the instructions before you begin,
and make sure you have the tools and skills
required.
• To help prevent the motorcycle from falling
over, park it on a firm, level surface, using the
side stand or an optional workstand to provide
support.
• To reduce the possibility of a fire or
explosion, be careful when working around
gasoline. Use only a non-flammable (high
flash point) solvent such as kerosene —not
gasoline— to clean parts. Keep cigarettes,
sparks, and flames away from all fuel-related
parts.
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26 Servicing Your Honda
Maintenance Schedule
To maintain the safety and reliability of your
CRF, regular inspection and service is required
as shown in the Maintenance Schedules –
Regular OFF ROAD Use (non-competition) and
Competition Use – that follow.
The Maintenance Schedule list items that can be
performed with basic mechanical skills and hand
tools. Procedures for these items are provided in
this manual.
The Maintenance Schedule also includes items
that involve more extensive procedures and may
require special training, tools, and equipment.
Therefore, we recommend that you have your
dealer perform these tasks unless you have
advanced mechanical skills and the required
tools. Procedures for items in these schedules
are provided in a service manual available for
purchase from your dealer (page 174).
Because your CRF does not have an odometer,
service intervals in the maintenance schedules
are expressed in terms of riding days as well as
miles. To avoid overlooking required service, we
urge you to develop a convenient way to record
the number of days and/or distance traveled
(USA: miles, Canada: kilometers) you ride.
If you do not feel capable of performing a given
task or need assistance, remember that your
Honda dealer knows your CRF best and is fully
equipped to maintain and repair it. If you decide
to do your own maintenance, use only Honda
Genuine Parts or their equivalents for repair
or replacement to ensure the best quality and
reliability.
Perform the pre-ride inspection (page 11) at each
scheduled maintenance period.
Each item on the maintenance schedule requires
some mechanical knowledge. Certain items
(particularly those marked *and**) may require
more technical information and tools. Consult
your dealer.
* Should be serviced by your dealer, unless the
owner has the proper tools and service data
and are mechanically qualified.
Refer to the official Honda Service Manual
(page 174).
** In the interest of safety, we recommend these
items be serviced only by your dealer.
Maintenance Procedures:
I: inspect and clean, adjust, lubricate, or replace,
if necessary
C: clean
A: adjust
L: lubricate
R: replace
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Servicing Your Honda 27
Maintenance Schedule
Summary of Maintenance Schedule Notes and
Procedures;
NOTES:
1. Service more frequently when ridden in wet
or dusty conditions.
2. USA and Canada type only.
3. Replace every 2 years. Replacement requires
mechanical skill.
FUEL LINE
FUEL STRAINER SCREEN
THROTTLE OPERATION
AIR CLEANER
CRANKCASE BREATHER
SPARK PLUG
VALVE CLEARANCE
ENGINE OIL
ENGINE OIL FILTER
DECOMPRESSOR SYSTEM
ENGINE IDLE SPEED
RADIATOR COOLANT
COOLING SYSTEM
SECONDARY AIR SUPPLY SYSTEM
TRANSMISSION OIL
DRIVE CHAIN
DRIVE CHAIN SLIDER
BRAKE FLUID
BRAKE PADS WEAR
BRAKE SYSTEM
HEADLIGHT AIM
CLUTCH SYSTEM
SIDE STAND
SUSPENSION
SPARK ARRESTER
NUTS, BOLTS, FASTENERS
WHEELS/TIRES
STEERING HEAD BEARINGS
(NOTE 1)
(NOTE 3)
(NOTE 1)
(NOTE 3)
I
R
R
I
I
I
R
I, L
I
I
I
I
I
C
I
I
I
R
R
I
I
I
R
I
I
I
I
I
I
I
C
I
C
I
I
I
R
R
I
I
I
I
I
R
I
I
I
I
I
I
I
I
I
I
I
C
I
I
I
R
R
I
I
I
R
I
I
I
I
I
I
I
C
I
C
I
I
I
R
R
I
I
R
I
I
R
I
I
I
I
I
I
I
I
I
I
I
41
42
55
51
53
61
66
43
44
–
14
0
48
49
–
46
96 – 98
98
89
91
88
107
56
95
84, 85
65
103, 160
–
163
92, 93
102
FREQUENCY
ITEMS
NOTE
miles
km
Month
100
150
1
600
1,000
6
1,200
2,000
12
I, L: every 300 miles (500 km) or 3 months
C: every 1,000 miles (1,600 km) or
every 100 operating hours
1,800
3,000
18
2,400
4,000
24
Refer
to
Page:
Whichever
Comes First
Initial
Maint
Regular Maintenance Interval
Should be serviced by your dealer, unless the owner has the proper tools and service data and is mechanically qualified. Refer to the official Honda
Service Manual (page 174).
In the interest of safety, we recommend these items be serviced only by your dealer.
*
**
(NOTE 2)
MAINTENANCE SCHEDULE – REGULAR OFF-ROAD USE (NON-COMPETITION)
17CRF450X31MEY710.indb27 2016/06/0811:45:34
28 Servicing Your Honda
MAINTENANCE SCHEDULE – COMPETITION USE
All items should be checked before each competition event. See your dealer unless you are mechanically qualified and have the proper tools.
Damage from competition use is not covered by the Distributor’s Limited Warranty on your Honda.
Perform the Pre-ride Inspection (page 11) at each scheduled maintenance period.
I: Inspect and Clean, Adjust, Lubricate or Replace if necessary. C: Clean. A: Adjust. L: Lubricate. R: Replace.
Maintenance Schedule
ITEMS
THROTTLE OPERATION
HOT STARTER
AIR FILTER
CRANKCASE BREATHER
SPARK PLUG
RADIATOR COOLANT
VALVE CLEARANCE / DECOMPRESSOR SYSTEM
ENGINE OIL
ENGINE OIL FILTER
ENGINE IDLE SPEED
PISTON AND PISTON RINGS
PISTON PIN
TRANSMISSION OIL
COOLING SYSTEM
DRIVE CHAIN
DRIVE CHAIN SLIDER
DRIVE CHAIN ROLLER
DRIVE SPROCKET
DRIVEN SPROCKET
BRAKE FLUID
BRAKE PADS WEAR
BRAKE SYSTEM
CLUTCH SYSTEM
CONTROL CABLES
EXHAUST PIPE/MUFFLER
SUSPENSION
SWINGARM/SHOCK LINKAGE
FORK OIL
NUTS, BOLTS, FASTENERS
WHEELS/TIRES
STEERING HEAD BEARINGS
(NOTE 1)
(NOTE 2)
(NOTE 4)
(NOTE 3)
(NOTE 3)
(NOTE 5)
(NOTE 2)
(NOTE 5)
(NOTE 3)
55
60
51
53
61
48
66
43
44
140
79
79
46
49
96
98
98
97
97
89
91
88
56
102
62
84, 85
32
86
117
103, 160 – 163
92, 93
102
I
I
C
I
I
I
I
I
I
I
I, L
I
I
I
I
I
I
I
I
I, L
I
I
I
I
R
L
R
I
R
R
R
R
R
I
R
FORK TUBE/SLIDER
DAMPER
FREQUENCY
NOTE Ref. Page
About
2.5 hours
About
7.5 hours
About
15.0 hours
About
22.5 hours
About
30.0 hours
* We recommended these items be serviced by referring to the Honda service manual.
This maintenance schedule is based upon average riding condition. Machine subjected to severe use require more frequent servicing.
NOTE: 1. Clean after every moto for dusty riding conditions.
2. Replace every 2 years. Replacement requires mechanical skill.
3. Replace after the first break-in ride.
4. Inspect after the first break-in ride.
5. Replace the transmission oil, if the clutch discs and plates are replaced.
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Servicing Your Honda 29
General Competition Maintenance
Perform maintenance on firm, level ground
using the side stand, a workstand, or equivalent
support.
When tightening bolts, nuts or screws, start with
the larger diameter or inner fasteners, and tighten
them to the specified torque using a crisscross
pattern.
Use Honda Genuine Parts or their equivalent
when servicing your CRF.
Clean parts in non-flammable (high flash point)
cleaning solvent (such as kerosene) when
disassembling. Lubricate any sliding surface, O-
rings, and seals before reassembling. Grease parts
by coating or filling where specified.
After any engine disassembly, always install
new gaskets, O-rings, cotter pins, piston pin
clips, snap rings, etc. when reassembling. After
reassembly, check all parts for proper installation
and operation.
All Pre-ride Inspection Item
Refer to Pre-ride Inspection page 11.
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30 Servicing Your Honda
General Competition Maintenance
Spark Plug
Some non-resistor plugs may cause ignition problems. Refer
to the recommendations elsewhere in this manual for specic
types so you will be sure to use the proper reach and heat
range. Replace periodically as specied in the Maintenance
Schedule (pages 27, 28).
Spark Plug Cap
Install a small plastic tie-wrap around the spark plug cap to
reduce any possibility of it loosening or of water
penetration.
Engine Oil and Filter
Drain and replace engine oil often to ensure the greatest
service life of the piston, cylinder and crankshaft.
Also replace engine oil lter often to ensure the greatest
service life. Frequent changes will also assure consistent
performance of power and response (page 44).
Transmission Oil
Drain and replace transmission oil often to ensure the
greatest service life of the transmission and clutch. Frequent
changes will also assure consistent performance of both
shifting and clutch action (page 47).
Air Cleaner Housing Sealing
Remove and reseal the air cleaner connecting boot where it
connects to the air cleaner housing with Pro Honda Handgrip
Cement or equivalent if there is any doubt to its sealing
integrity. Inspect the air cleaner and air intake tract regularly
for signs of deterioration or dirt penetration.
Air Cleaner
Clean and oil your air cleaner regularly because the volume
of air able to pass through it has a great effect on
performance. Both engine performance and long term
durability may be affected by an air cleaner that has
deteriorated and allows dirt to pass. Inspect the air cleaner
closely each time it’s serviced for evidence of small tears or
seam separation. Keep a spare air cleaner oiled and ready to
install, sealed in a plastic bag. Riding in dusty conditions
may require servicing the air cleaner or replacing it with a
pre-serviced air cleaner between motos. Be careful not to
over oil the air cleaner. While it is important to oil the air
cleaner thoroughly, over oiling will cause an overall rich
running condition, probably more noticeable off idle and in
low rpm performance. Follow the servicing instructions in
the Maintenance section. Use Pro Honda Foam Filter Oil or
an equivalent. Be sure to grease the air cleaner ange where
it contacts the air cleaner housing. Pro Honda White Lithium
Grease, or an equivalent, is handy for this because any dirt
that penetrates this sealing area will show up clearly (page
51).
Use the Honda Genuine air cleaner or an equivalent air
cleaner specied for your model.
Using the wrong Honda air cleaner or a non-Honda air
cleaner which is not of equivalent quality may cause
premature engine wear or performance problems.
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Servicing Your Honda 31
General Competition Maintenance
Handgrips
Always use Pro Honda Handgrip Cement or equivalent when
replacing handgrips.
Throttle Grip
Align the index mark on the throttle grip with the edge of the
throttle cable guide. Left handlebar grip: Align the “ ” mark
on the left handlebar grip with the paint mark on the
handlebar.
Refer to the Honda Service Manual (page 174)
for installation instructions.
For added security, you may choose to bind the handgrips to
the handlebar and throttle pipe with safety wire to prevent
the possibility of them loosening. Position the twisted wire
ends away from your palms and be sure to bend the wire
ends well into the handgrips rubber so they will not snag
your glove.
Throttle Control
Remove the throttle control every few rides, clean the inside
of the throttle pipe and handlebar thoroughly.
Inspect the cable carefully for kinks or other damage that
may restrict throttle control in any way. Move the handlebar
from lock to lock to be sure there is no cable interference.
Make certain the throttle operation is perfect after servicing
and inspecting.
Gaskets
Always use new gaskets when reassembling components.
Cylinder
Put a little grease on the cylinder mounting dowels to
prevent corrosion from dissimilar metals. The tolerances are
quite tight, so it’s important to keep these dowels absolutely
clean (page 78).
Fuel Filter
Periodically drain the fuel from the fuel tank, remove and
clean the fuel valve/lter. Replace the fuel valve O-ring if
there are any signs of damage or deterioration (page 42).
Fuel Contamination
Refer to Fuel System in your Owner’s Manual (page 41).
Check the fuel lines for deterioration, damage, or leakage.
Replace the fuel lines, if necessary.
Periodically drain the fuel from the fuel tank, remove and
clean the fuel valve/lter. Replace the fuel valve O-ring if
there are any signs of damage or deterioration (page 42).
Loosen the carburetor drain screw and examine the fuel that
ows out of the oat bowl. If you notice anything in the fuel,
such as water or dirt, remove the oat bowl and inspect its
contents (page 137).
For maximum efciency, drain and replace fuel that has
remained in your fuel tank for more than a month.
Engine Mounting Bolts and Nuts
Make sure the engine mounting bolts and nuts are tightened
to the proper torque specication. For added peace of mind,
remove the nuts, clean the threads, and apply Pro Honda
Hondalock or an equivalent prior to torquing the nuts.
Electrical Connectors
Clean electrical connectors and wrap them with electrical
tape to reduce the possibility of unwanted disconnections,
water shorts or corrosion. Additional corrosion protection is
offered by using Pro Honda Dielectric Grease on all
electrical connections.
Battery
Electrical accessories use current from the battery – even
when the engine is off.
Limited operation also allows the battery to discharge. If you
have electrical accessories on your CRF – or do not ride
frequently, we recommend that you charge the battery
frequently (see Battery Charging, page 105).
If you do not expect to ride your CRF for at least 2 weeks,
we recommend you remove the battery – or at least
disconnect the battery cables (negative cable rst).
Fuse
Check the fuse before looking elsewhere for the cause of an
electrical problem.
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32 Servicing Your Honda
General Competition Maintenance
Swingarm Pivot Lubrication
Clean, inspect and lubricate the swingarm and suspension
linkage pivots with grease. Be sure all of the dust seals are in
good condition.
Swingarm
Do not attempt to weld or otherwise repair a damaged
swingarm. Welding will weaken the swingarm.
Footpegs
Worn footpeg teeth can be repaired by ling the grooves
between the teeth with a triangular shaped le.
Be aware that ling them too sharp will reduce boot sole
lifespan. Sharpen only the points of the teeth. Filing the
grooves deeper will weaken the footpegs. Be sure the
footpegs are free to pivot freely and that the pivot pin
retaining cotter pins are in good condition.
Brake Fluid Replacement
Refer to Brake Pad Wear in your Owner’s Manual (page 91).
Brake Caliper Inspection: Be sure both the front and rear
calipers are able to move freely on the caliper pins and
caliper bracket pins.
Check pad thickness periodically and replace the pads when
minimum thickness is reached. If the brakes fade when they
are hot, inspect the pads for glazing or damage, and replace
if necessary.
Brake Fluid Replacement: Refer to the Honda Service
Manual (Page 174) for brake uid replacement instructions.
Replace the hydraulic uid in the brake system every 2
years. Replace the uid more frequently if you subject your
brakes to severe use. Heavy braking heats the brake uid and
it may deteriorate sooner than expected. Any type of riding,
that requires frequent use of the brakes, such as in tight
woods, can shorten the service life of brake uid.
Steering Head Bearings
Periodically clean, inspect and regrease the steering head
bearings — especially if wet, muddy or extremely dusty
courses are encountered often.
Use urea based multi-purpose grease designed for high
temperature, high pressure performance (example:
EXCELITE EP2 manufactured by KYODO YUSHI, Japan
or Shell Stamina EP2 or equivalent)
Bleed Hole
After every race, check the bleed hole, located just below the
water pump cover on the right crankcase cover. Clean away
any clogged dirt or sand, if necessary. Check for signs of seal
leakage. A small amount of “weeping” from the bleed hole is
normal.
Fork Oil/Performance
Disassemble, clean and inspect the front fork and replace oil
regularly. Contamination due to the tiny metal particles
produced from the normal action of the fork, as well as
normal oil breakdown, will deteriorate the performance of
the suspension. Refer to the Honda Service Manual
(page 174). Use only Pro Honda HP Fork Oil 5W or
equivalent which contains special additives to assure
maximum performance of your CRF’s front suspension.
Frame
Because your CRF is a high-performance machine, the frame
should not be overlooked as part of your overall competition
maintenance program. Periodically inspect the frame
closely for possible cracking or other damage. It makes good
racing sense.
Spokes
Check spoke tension frequently between the rst few rides.
As the spokes, spoke nuts and rim contact points seat-in, the
spokes may need to be retightened. Once past this initial
seating-in period, the spokes should hold their tension. Still,
be sure your race maintenance program includes checking
spoke tension and overall wheel condition on a regular basis
(page 92).
Nuts, Bolts, Etc.
Application of a thread locking agent to essential fasteners
offers added assurance and security. Remove the nuts, clean
the threads of both the nuts and bolts, apply Pro Honda
Hondalock or an equivalent and tighten to the specied
torque.
Suspension Linkage Lubrication
Disassemble, clean, inspect and lubricate all suspension
linkage pivot bearings with grease after each 7.5 hours of
running time in order to maintain proper suspension
performance and minimize component wear.
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Servicing Your Honda 33
Before & After Competition Maintenance
Between Motos & Practice Maintenance
After practice or between motos you have
a chance to make additional checks and
adjustments.
• Clean accumulated dirt from under the fenders
and off the wheels, suspension components,
handgrips, controls, and footpegs. A stiff,
nylon parts cleaning brush works well.
• Check tire air pressure.
•
Check spoke tension and rim lock security.
• Check to make sure the sprocket bolts and
nuts are secure.
• Clean the sides of the drive chain with a stiff,
nylon parts-cleaning brush. Lubricate and
adjust the chain as necessary.
Do not perform maintenance while engine is
running. Injury to your fingers or hands may
result.
• After adjustment, check that the chain adjuster
index marks (1) are in the same position on
each side. This will ensure that the rear wheel
is in proper alignment and allow maximum
performance from the rear disc brake.
Maintaining proper wheel alignment will also
extend brake pad wear.
After Competition Maintenance
It is important to the long term performance of
your CRF to practice a consistent maintenance
program. Right after the event is a good time to
begin your next maintenance cycle.
After Race Lubrication
Apply a light coating of rust-inhibiting oil to
the drive sprocket and any steel portions of the
chassis or engine where the paint has worn away.
This will prevent rusting of the exposed metal.
Apply rust-inhibiting oil more heavily if the
event was particularly wet or muddy. Take care to
avoid spraying any oil near the brake pads or the
brake disc.
Clean and lubricate the drive chain (page 98). Be
sure the chain is wiped clean and is dry before
lubricating the chain.
Take care to prevent catching your fingers
between the chain and sprocket.
(1)
(1) chain adjuster index marks
• Suspend the front wheel above the ground
and use the fork air pressure release screws
(2) to release the built-up pressure (in excess
of normal atmospheric pressure: 0 psi (0 kPa,
0 kgf/cm
2
)) in the fork tubes. This pressure
is caused by normal fork action while riding.
(If you are riding at altitude, remember that
fork pressure of 0 at sea level will increase as
elevation increases.)
(2)
(2) fork air pressure release screw
17CRF450X31MEY710.indb33 2016/06/0811:45:35
34 Servicing Your Honda
Before & After Competition Maintenance
Routine Cleaning
If your CRF is only slightly dirty, it is best to
clean it by hand with the aid of a stiff bristled
nylon brush and some clean rags.
Take care to prevent catching your fingers
between the chain and sprocket.
A variety of reasonably priced cleaning brushes
are available from variety, drug, food, and
hardware stores. Some of these brushes are
extremely useful in removing dirt from the many
tight contours of the metal pieces of your CRF.
Avoid using stiff, abrasive brushes on the plastic
or rubber parts.
If your CRF was exposed to sea air or salt water,
rinse it as soon as possible after the event, dry it,
and apply a spray lubricant to all metal parts.
If you decide to wash your CRF or use cleaners,
refer to Appearance Care (page 108).
17CRF450X31MEY710.indb34 2016/06/0811:45:35
Servicing Your Honda 35
Maintenance Component Locations
throttle stop screw
(engine idle speed)
choke knob
rear suspension spring
pre-load adjuster
spark arrester
crankcase breather tube
drive chain
coolant reserve tank
coolant reserve tank cap
front brake caliper
engine
oil filter
transmission
oil drain bolt
engine oil drain bolt
engine oil fill cap/dipstick
air cleaner
spark plug
battery
main fuse
rear suspension high speed
compression damping adjuster
rear suspension low speed
compression damping adjuster
rear suspension
rebound damping
adjuster
front suspension
compression damping
adjuster
transmission oil
fill cap
transmission
oil check bolt
front suspension rebound
damping adjuster
rear brake
pedal
rear brake fluid
reservoir
rear brake
caliper
clutch lever
hot start lever
steering damper adjuster
front brake lever
fuel fill cap
throttle grip
radiator cap
front brake fluid reservoir
17CRF450X31MEY710.indb35 2016/06/0811:45:35
36 Servicing Your Honda
Seat
Refer to Safety Precautions on page 25.
Removal
1. Remove the seat mounting bolts (1).
2. Remove the seat (2) by sliding it backward.
(1)
(2)
(1) seat mounting bolts
(2) seat
Installation
1. Install the seat (1) while aligning the seat
front prong (2) with the seat bracket (3) and
seat rear prongs (4) with the tabs (5) of the
frame.
2. Install and tighten the seat mounting bolts (6)
to the specified torque.
19 lbf·ft (26 N·m, 2.7 kgf·m)
(2)
(4)
(1)
(6)
(3)
(5)
(1) seat
(2) seat front prong
(3) seat br
acket
(4) seat rear prongs
(5) tabs
(6) seat mounting bolts
17CRF450X31MEY710.indb36 2016/06/0811:45:35
Servicing Your Honda 37
Fuel Tank
Refer to Safety Precautions on page 25.
Removal
1. Turn the fuel valve OFF.
2. Remove the seat (page 36).
3. Remove the shroud A bolts/collars (1).
4. Remove the shroud B bolts (2) and shrouds
(3).
(3)
(2)
(1)
(1) shroud A bolts/collars
(2) shroud B bolts
(3) shroud
5. Pull the breather tube (4) out of steering stem
nut.
6. Unhook and remove the fuel tank band (5).
7. Unhook the air cleaner cover rubber (6).
8. Remove the fuel tank bolt (7).
(4)
(7)
(6)
(5)
(4) breather tube
(5) fuel tank band
(6) air cleaner cov
er rubber
(7) fuel tank bolt
9. Disconnect the fuel line (8) from the fuel
valve (9). The fuel line leading to the
carburetor must be disconnected, not the fuel
line leading to the fuel tank.
10. Remove the fuel valve bolt (10) and fuel
valve.
11. Remove the fuel tank.
Gasoline is highly ammable and
explosive. You can be burned or seriously
injured when handling fuel.
• Stop the engine and keep heat, sparks
and ame away.
• Handle fuel only outdoors.
• Wipe up spills immediately.
WARNING
(10)
(9)
(8)
(8) fuel line
(9) fuel val
ve
(10) fuel valve bolt
17CRF450X31MEY710.indb37 2016/06/0811:45:36
38 Servicing Your Honda
Fuel Tank
Installation
1. Install the fuel tank on the frame.
2. Install the fuel valve (1) and tighten the fuel
valve bolt (2).
3. Connect the fuel line (3) to the fuel valve.
Clamp the fuel line clamp (4) as shown.
(1)
(2)
(3)
(4)
0 – 0.1 in (0 – 3 mm)
(1) fuel valve (3) fuel line
(2) fuel valve bolt (4) fuel line clamp
4. Install and tighten the fuel tank bolt (5).
5. Hook the air cleaner cover rubber (6).
6. Install and hook the fuel tank band (7).
7. Put the breather tube (8) in the steering stem
nut.
(8)
(5)
(6)
(7)
(5) fuel tank bolt (7) fuel tank band
(6) air cleaner cover r
ubber (8) breather tube
8. Install the shrouds (9) by aligning its tab (10)
with subframe (11).
(9)
(11)
(10)
(9) shroud
(10) tab
(1
1) subframe
9. Install the shroud B bolts (12) and shroud A
bolts/collars (13).
10. Tighten the shroud B bolts to the specified
torque:
3.7 lbf·ft (5 N·m, 0.5 kgf·m)
(12)
(13)
(12) shroud B bolts
(13) shroud A bolts/collars
11. Install the seat (page 36).
17CRF450X31MEY710.indb38 2016/06/0811:45:36
Servicing Your Honda 39
Subframe Upright Position
Refer to Safety Precautions on page 25.
The subframe may be adjusted to an upright
position to permit servicing of the rear
suspension and carburetor.
Upright Position
1. Remove the seat (page 36).
2. Remove the right side cover bolt (1) and right
side cover (2).
(2)
(1)
(1) right side cover bolt
(2) right side cov
er
3. Open the air cleaner housing cover
(3) by turning the quick fastener (4)
counterclockwise and remove the left side
cover bolt (5) and left side cover (6).
(6)
(5)
(3)
(4)
(3) air cleaner housing cover (5) left side cover bolt
(4) quick fast
ener (6) left side cover
4. Remove the muffler (page 62).
5. Loosen the screw (7) on the air cleaner
connecting boot clamp (8).
(7)
(8)
(7) screw
(8) air cleaner connecting boot clamp
6. Loosen the subframe upper mounting bolts
(9) and remove the subframe lower mounting
bolts (10).
(9)
(10)
(9) subframe upper mounting bolts
(10) subframe lo
wer mounting bolts
7. Lift the subframe (11) as shown.
Tighten the subframe upper mounting bolts to
the specified torque:
36 lbf·ft (49 N·m, 5.0 kgf·m)
90°
(11)
(11) subframe
17CRF450X31MEY710.indb39 2016/06/0811:45:36
40 Servicing Your Honda
Subframe Upright Position
3. Make sure the carburetor lug (4) aligns with
the air cleaner connecting tube slot (5).
4. Tighten the screw (6) on the air cleaner
connecting boot clamp (7).
(6)
(7)
(5)
(4)
(4) carburetor lug
(5) air cleaner connecting tube slot
(6) screw
(7) air cleaner connecting boot clamp
Installation
1. Loosen the subframe upper mounting bolts
(1).
2. Loosely attach the lower ends of the subframe
(2) to the mainframe while connecting the air
cleaner connecting boot to the carburetor. Be
careful not to bend the subframe. Install the
subframe lower mounting bolts (3).
Tighten the subframe upper mounting
bolts first, then tighten the subframe lower
mounting bolts to the specified torque:
36 lbf·ft (49 N·m, 5.0 kgf·m)
(1)
(2)
(3)
(1) subframe upper mounting bolts
(2) subframe
(3) subframe lo
wer mounting bolts
5. Install the muffler (page 63).
6. Install the left side cover (8) and left side
cover bolt (9). Close the air cleaner housing
cover (10) and turn the quick fastener (11)
clockwise.
(8)
(9)
(11)
(10)
(8) left side cover (10) air cleaner housing cover
(9) left side cover bolt (11) quick fastener
7. Install the right side cover (12) and right side
cover bolt (13).
(12)
(13)
(12) right side cover
(1
3) r
ight side co
ver bolt
8. Install the seat (page 36).
17CRF450X31MEY710.indb40 2016/06/0811:45:36
Servicing Your Honda 41
Fuel System
Refer to Safety Precautions on page 25.
Fuel Recommendation
Type Unleaded
Pump Octane Number 91 (or higher)
Use only unleaded fuel in your Honda. If you
ride your Honda in a country where leaded fuel
might be available, take precautions to use only
unleaded fuel.
Your engine is designed to use any unleaded
gasoline that has a pump octane number of 91
or higher. Gasoline pumps at service stations
normally display the pump octane number. For
information on the use of oxygenated fuels, see
page 166.
Use of lower octane gasoline can cause persistent
“pinging” or “spark knock” (a louder rapping
noise) which, if severe, can lead to engine
damage. (Light pinging experienced while
operating under a heavy load, such as climbing a
hill, is no cause for concern.)
If pinging or spark knock occurs at a steady
engine speed under normal load, change brands
of gasoline. If pinging or spark knock persists,
consult your dealer.
Never use stale or contaminated gasoline. Avoid
getting dirt, dust, or water in the fuel tank.
Refueling Procedure
Fuel Tank Capacity: 1.90 US gal (7.2 ℓ)
(2)
(1)
(3)
(1) fuel ll
cap
(2) breather tube
(3) st
eering stem nut
1. To open the fuel fill cap (1), pull the breather
tube (2) out of the steering stem nut (3). Turn
the fuel fill cap counterclockwise and remove it.
2. Add fuel until the level reaches the bottom
of the filler neck. Avoid overfilling the tank.
There should be no fuel in the filler neck.
3. Close the fuel fill cap by turning the cap
clockwise and insert the breather tube in the
steering stem nut.
Gasoline is highly ammable and
explosive. You can be burned or seriously
injured when handling fuel.
• Stop the engine and keep heat, sparks
and ame away.
• Handle fuel only outdoors.
• Wipe up spills immediately.
WARNING
Fuel Line
(1)
(1)
(1) fuel line
1. Check for leaks.
2. Check the fuel line (1) for cracks,
deterioration, damage, or leakage. Replace
the fuel line, if necessary.
3. Check for interference between the frame and
tank and adjust if necessary.
17CRF450X31MEY710.indb41 2016/06/0811:45:37
42 Servicing Your Honda
Fuel System
Fuel Filter
The fuel filter is mounted on the bottom left side
of the fuel tank. Dirt accumulated in the filter
will restrict the flow of the fuel to the carburetor.
Therefore, the fuel filter should be serviced
frequently.
To service the fuel filter:
1. Remove the fuel tank (page 37).
2. Drain the fuel from the fuel tank into an
approved gasoline container. Disconnect the
fuel valve and fuel lines (1).
3. Remove the fuel joint (2) from the fuel tank
by removing the bolts (3).
(1) fuel valve and fuel lines
(2) fuel joint
(3) bolts
(1)
(3)
(2)
4. Wash the fuel filter (4) in high flash-point
cleaning solvent.
5. Check that the O-ring (5) is in good
condition.
6. Install the fuel joint in the fuel tank by
tightening the bolts to the specified torque:
7 lbf·ft (10 N·m, 1.0 kgf·m)
Attach the fuel valve and fuel lines.
7. Install the fuel tank (page 38). Refill the fuel
tank and turn the fuel valve to ON or RES;
check for fuel leaks.
(5)
(4)
(4) fuel lter
(5) O-ring
17CRF450X31MEY710.indb42 2016/06/0811:45:38
Servicing Your Honda 43
Engine Oil
Refer to Safety Precautions on page 25.
Using the proper oil, and regularly checking,
adding, and changing oil will help extend the
service life of the engine. Even the best oil
wears out. Changing oil helps get rid of dirt and
deposits. Operating the engine with old or dirty
oil can damage your engine. Running the engine
with insufficient oil can cause serious damage to
the engine.
Oil Recommendation
API
classi cation
SG or higher except oils labeled
as energy conserving or resource
conserving on the circular API
service label
viscosity
(weight)
SAE 10W-30
JASO T 903
standard
MA
suggested oil* Pro Honda GN4 4-stroke oil (USA
& Canada), or Honda 4-stroke oil,
or an equivalent motorcycle oil*
* Suggested 4-stroke engine oils are equal
performance to SJ oils that are not labeled as
energy conserving or resource conserving on
the circular API service label.
• Your CRF does not need oil additives.
Use the recommended oil.
• Do not use API SH or higher 4-stroke
engine oils displaying a circular API “energy
conserving” or “resource conserving” service
label on the container. They may affect
lubrication.
NOT RECOMMENDED OK
• Oil is a major factor affecting the performance
and service life of the engine.
Other viscosities shown in the following chart
may be used when the average temperature in
your riding area is within the indicated range.
17CRF450X31MEY710.indb43 2016/06/0811:45:38
44 Servicing Your Honda
Engine Oil
JASO T 903 standard
The JASO T 903 standard is an index for engine
oils for 4-stroke motorcycle engines.
There are two classes: MA and MB.
Oil conforming to the standard is labeled on the
oil container.
For example, the following label shows the MA
classification.
(1)
(2)
(1) oil code
(2) oil classi cation
Changing Engine Oil & Filter
1. Run the engine at idle for 3 minutes, then
shut it off.
2. Support the CRF in an upright position on a
level surface.
3. Remove the engine oil fill cap/dipstick (1)
from the left crankcase cover.
4. Place an oil drain pan under the engine to
catch the oil. Then remove the engine oil
drain bolt (2) and sealing washer (3).
5. After the oil has drained, apply engine oil to
the drain bolt threads and tighten it with a
new sealing washer to the specified torque:
12 lbf·ft (16 N·m, 1.6 kgf·m)
Pour the drained oil into a suitable container and
dispose of it in an approved manner (page 151).
NOTICE
Improper disposal of drained fluids is harmful to
the environment.
(1)
(2)
(3)
(1) engine oil ll cap/dipstick
(2) engine oil dr
ain bolt
(3) sealing washer
Checking & Adding Oil
(1)
(2)
(3)
(1)
(1) engine oil ll cap/dipstick
(2) upper le
vel mark
(3) lower level mark
1. Run the engine at idle for 3 minutes, then
shut it off.
2. Wait 3 minutes after shutting off the engine
to allow the oil to properly distribute itself in
the engine.
3. Support the CRF in an upright position on a
level surface.
4. Remove the engine oil fill cap/dipstick (1),
wipe it clean, and insert the engine oil fill
cap/dipstick without screwing it in. Remove
the engine oil fill cap/dipstick.
5. Check that the oil level is between the upper
(2) and lower (3) level marks on the engine
oil fill cap/dipstick.
• If the oil is at or near the upper level mark,
you do not have to add oil.
• If the oil is below or near the lower level
mark, add the recommended oil until the
upper level mark. (Do not overfill)
Reinstall the engine oil fill cap/dipstick.
Repeat steps 1 – 5.
6. Install the engine oil fill cap/dipstick securely.
7. Check for oil leaks.
17CRF450X31MEY710.indb44 2016/06/0811:45:38
Servicing Your Honda 45
Engine Oil
6. It is recommended to replace the oil and filter
every 15.0 hours. However, if you replace
only the oil before the recommended interval,
see pages 27, 28.
7. Remove the left engine guard bolt (4) and left
engine guard (5).
(5)
(4)
(4) left engine guard bolt
(5) left engine guard
NOTICE
If the oil filter is not installed properly, it will
cause serious engine damage.
12. Apply engine oil to a new O-ring and install
it to the oil filter cover.
13. Install the oil filter cover being careful not to
damage the O-ring, then tighten the oil filter
cover bolts to the specified torque:
7 lbf·ft (10 N·m, 1.0 kgf·m)
14. Install the left engine guard and tighten the
left engine guard bolt.
15. Fill the crankcase with the recommended oil.
Capacity: 0.74 US qt (0.70 ℓ)
after draining and filter change
0.71 US qt (0.67 ℓ)
after draining
16. Install the engine oil fill cap/dipstick.
17. Check the engine oil level by following the
steps in Checking & Adding Oil (page 44).
Pour the drained oil into a suitable container and
dispose of it in an approved manner (page 151).
NOTICE
Improper disposal of drained fluids is harmful to
the environment.
8. Remove the oil filter cover bolts (6), oil filter
cover (7) and O-ring (8).
9. Remove the oil filter (9) and spring (10) from
the filter cover.
10. Apply grease to the filter side of the spring
end, then install the spring into a new oil
filter.
(8)
(7)
(6)
(11)
(10)
(9)
(12)
(6) oil lter cover bolts
(7) oil lt
er cover
(8) oil lter cover O-ring
(9) oil lter
(10) spring
(11) rubber seal
(12) “OUT-SIDE” mark
NOTICE
Using the wrong oil filter may result in leaks or
engine damage.
11. Position the spring against the engine
crankcase and install a new oil filter with
the rubber seal (11) facing out, away from
the engine. You should see the “OUT-SIDE”
mark (12) on the filter body, near the seal.
Use a new Honda Genuine oil filter or a filter
of equal quality specified for your model.
17CRF450X31MEY710.indb45 2016/06/0811:45:40
46 Servicing Your Honda
• Oil is a major factor affecting the performance
and service life of the transmission and clutch.
Other viscosities shown in the following chart
may be used when the average temperature in
your riding area is within the indicated range.
JASO T 903 standard
The JASO T 903 standard is an index for engine
oils for 4-stroke motorcycle engines.
There are two classes: MA and MB.
Oil conforming to the standard is labeled on the
oil container.
For example, the following label shows the MA
classification.
(1)
(2)
(1) oil code
(2) oil classi cation
Oil Recommendation
API classi cation
(4-stroke engine
oil only)
SG or higher except oils
labeled as energy conserving
or resource conserving on the
circular API service label
Viscosity (weight) SAE 10W–30
JASO T 903
standard
MA
others without friction modi ers such
as molybdenum additives
suggested oil* Pro Honda GN4 4-stroke oil
(USA & Canada), or Honda
4-stroke oil, or an equivalent
motorcycle oil*
* Suggested 4-stroke engine oils are equal
performance to SJ oils that are not labeled as
energy conserving or resource conserving on
the circular API service label.
• Your CRF does not need oil additives. Use the
recommended oil.
• Do not use oils with graphite or molybdenum
additives. They may adversely affect clutch
operation.
• Do not use API SH or higher 4-stroke engine
oils displaying a circular API “energy
conserving” or “resource conserving” service
label on the container. They may affect
lubrication and clutch performance.
NOT RECOMMENDED OK
Transmission Oil
Refer to Safety Precautions on page 25.
Using the proper oil, and regularly checking,
adding, and changing oil will help extend the
service life of the transmission and clutch. Even
the best oil wears out. Changing oil helps get rid
of dirt and deposits. Operating the engine with
old or dirty oil can damage your engine. Running
the engine with insufficient oil can cause serious
damage to the engine and transmission.
17CRF450X31MEY710.indb46 2016/06/0811:45:40
Servicing Your Honda 47
Replacing Transmission Oil
1. Run the engine at idle for 3 minutes, then
shut it off.
2. Support the CRF in an upright position on a
level surface.
3. Remove the transmission oil fill cap (1) from
the right crankcase cover.
4. Place an oil drain pan under the engine to
catch the oil. Then remove the transmission
oil drain bolt (2) and sealing washer (3).
5. After the oil has drained, apply engine oil to
the drain bolt threads and tighten it with a
new sealing washer to the specified torque:
12 lbf·ft (16 N·m, 1.6 kgf·m)
(1)
(2)
(3)
(1) transmission oil ll cap
(2) transmission oil dr
ain bolt
(3) sealing washer
6. Fill the crankcase with recommended oil.
Capacity: 0.69 US qt (0.65
ℓ
) after draining.
7. Check the transmission oil level by following
the steps in Checking & Adding Oil (this
page).
Checking & Adding Oil
(1)
(2)
(3)
(1) transmission oil ll cap (3) sealing w
asher
(2) oil check bolt
1. Run the engine at idle for 3 minutes, then
shut it off.
2. Wait 3 minutes after shutting off the engine
to allow the oil to properly distribute itself in
the clutch and transmission.
3. Support the CRF in an upright position on a
level surface.
4. Remove the transmission oil fill cap (1), oil
check bolt (2) and sealing washer (3) from
the right crankcase cover. A small amount of
oil should flow out of the oil check bolt hole.
Allow any excess oil to flow out of the oil
check bolt hole. If no oil flows out of the oil
check bolt hole, add oil slowly through the
transmission oil fill hole until oil start to flow
out of the oil check bolt hole.
Install the oil check bolt with a new sealing
washer and transmission oil fill cap. Repeat
step 1 – 4.
5. After checking the oil level or adding oil,
install the oil check bolt with a new sealing
washer. Tighten the oil check bolt to the
specified torque:
7 lbf·ft (10 N·m, 1.0 kgf·m)
6. Install the transmission oil fill cap securely.
Transmission Oil
Pour the drained oil into a suitable container and
dispose of it in an approved manner (page 151).
NOTICE
Improper disposal of drained fluids is harmful to
the environment.
17CRF450X31MEY710.indb47 2016/06/0811:45:40
48 Servicing Your Honda
Coolant
Your CRF’s liquid cooling system dissipates
engine heat through the coolant jacket that
surrounds the cylinder and cylinder head.
Maintaining the coolant will allow the cooling
system to work properly and prevent freezing,
overheating, and corrosion.
Coolant Recommendation
Use Pro Honda HP Coolant or an equivalent high
quality ethylene glycol antifreeze containing
corrosion protection inhibitors specifically
recommended for use in aluminum engines.
Check the antifreeze container label.
Use only distilled water as a part of the coolant
solution. Water that is high in mineral content or
salt may be harmful to the aluminum engine.
NOTICE
Using coolant with silicate inhibitors may cause
premature wear of water seals or blockage of
radiator passages. Using tap water may cause
engine damage.
The factory provides a 50/50 solution of
antifreeze and water in this motorcycle. This
coolant solution is recommended for most
operating temperatures and provides good
corrosion protection.
Decreasing the concentration of antifreeze to
less than 40% will not provide proper corrosion
protection.
Increasing the concentration of antifreeze is
not recommended because it decreases cooling
system performance. Higher concentrations of
antifreeze (up to 60%) should only be used to
provide additional protection against freezing.
Check the cooling system frequently during
freezing weather.
Checking & Adding Coolant
Refer to Safety Precautions on page 25.
1. With the engine at normal operating
temperature, check the coolant level in
the reserve tank. It should be between the
UPPER (1) and LOWER (2) level marks.
If the reserve tank (3) is empty, or if coolant
loss is excessive, check for leaks and see your
dealer for repair.
(2)
(1)
(3)
(1) UPPER level mark (3) reserve tank
(2) LOWER level mark
2. Remove the reserve tank cap (4).
Always add coolant to the reserve tank.
Do not attempt to add coolant by removing
the radiator cap.
(4)
(4) reserve tank cap
3. Add coolant to the reserve tank as require to
bring the coolant level to the UPPER level
mark.
4. Install the reserve tank cap.
17CRF450X31MEY710.indb48 2016/06/0811:45:42
Servicing Your Honda 49
Coolant Replacement
Refer to Safety Precautions on page 25.
Coolant should be replaced by your dealer, unless
you have the proper tools and service data and
are mechanically qualified. Refer to the Honda
Service Manual (page 174).
Coolant
Removing the radiator cap while the
engine is hot can cause the coolant to
spray out, seriously scalding you.
Always let the engine and radiator cool
down before removing the radiator cap.
WARNING
Cooling System Inspection
1. Check the cooling system for leaks (see the
Honda Service Manual for troubleshooting of
leaks).
2. Check the water hoses (1) for cracks,
deterioration, and radiator hose clamp for
looseness.
3. Check the radiator mount for looseness.
4. Make sure the siphon hose (2) is connected
and not clogged.
5. Check the radiator fins for clogging.
6. Check the bleed hole (3) below the water
pump cover (4) for leakage. Check for signs
of seal leakage. A small amount of “weeping”
from the bleed hole is normal. See the Honda
Service Manual or consult your dealer for
replacing the water seal or the oil seal. Both
seals should be replaced at the same time.
(1) water hoses
(2) siphon hose
(3) bleed hole
(4) water pump cover
To properly dispose of drained coolant, refer to
You & the Environment, page 151.
NOTICE
Improper disposal of drained fluids is harmful to
the environment.
(1)
(2)
(1)
(4)
(3)
17CRF450X31MEY710.indb49 2016/06/0811:45:42
50 Servicing Your Honda
Coolant
Cooling System Bleed Air
1. Remove the radiator cap (1).
2. Fill the system with the recommended
coolant through the filler opening up to filler
neck (2). Use a fresh recommended coolant
mixture (page 48).
Capacity: 1.28 US qt (1.21 ℓ)
(1)
(2)
(1) radiator cap
(2) ller neck
3. Remove the reserve tank cap (3) and fill the
reserve tank to the UPPER level line (4).
(4)
(3)
(3) reserve tank cap
(4) UPPER level line
4. Bleed air from the system as follows:
• Shift the transmission into neutral. Start the
engine and let it idle 2 – 3 minutes.
• Snap the throttle three – four times to bleed
air from the system.
• Stop the engine and, if necessary, add
coolant up to the proper level. Reinstall the
radiator cap.
• Check the level of coolant in the reserve
tank and fill to the UPPER level if it is low.
NOTICE
If the radiator cap is not installed properly, it will
cause excessive coolant loss and may result in
overheating and engine damage.
5. Install the reserve tank cap.
17CRF450X31MEY710.indb50 2016/06/0811:45:42
Servicing Your Honda 51
Air Cleaner
Refer to Safety Precautions on page 25.
The air cleaner uses polyurethane inner and outer
pieces which can’t be separated.
A dirty air cleaner will reduce engine power.
Proper air cleaner maintenance is very important
for off-road vehicles. A dirty, water-soaked,
worn-out, or defective air cleaner will allow dirt,
dust, mud, and other impurities to pass into the
engine.
Service the air cleaner more frequently if you
ride in unusually wet or dusty areas. Your dealer
can help you determine the correct service
interval for your riding conditions.
Your CRF’s air cleaner has very specific
performance requirements. Use a new Honda
Genuine air cleaner specified for your model or
an air cleaner of equal quality.
NOTICE
Using the wrong air cleaner may result in
premature engine wear.
Proper air cleaner maintenance can prevent
premature engine wear or damage, expensive
repairs, low engine power, poor gas mileage, and
spark plug fouling.
NOTICE
Improper or lack of proper air cleaner
maintenance can cause poor performance and
premature engine wear.
Cleaning
1. Open the air cleaner housing cover
(1) by turning the quick fastener (2)
counterclockwise.
(1)
(2)
(1) air cleaner housing cover
(2) quick fast
ener
2. Remove the air cleaner element retaining bolt
(3).
3. Remove the air cleaner element assembly (4)
while turning it as shown.
(4)
(3)
(3) air cleaner element retaining bolt
(4) air cleaner element assembly
4. Remove the air cleaner element (5) from the
air cleaner holder (6).
(9)
(7)
(5)
(6)
(8)
(5) air cleaner element (8) hole
(6) air cleaner holder (9) air cleaner element tab
(7) tab
5. Wash the air cleaner element in clean non-
flammable cleaning solvent. Then wash in
hot, soapy water, rinse well, and allow to dry
thoroughly.
The air cleaner element is made in two
pieces: inner and outer, which cannot be
separated.
6. Clean the inside of the air cleaner housing.
7. Allow the air cleaner element to dry
thoroughly. After drying, soak the air cleaner
element in clean Pro Honda Foam Filter Oil
or an equivalent air cleaner oil.
Apply air cleaner oil to the entire surface of
the air cleaner element and rub it with both
hands to saturate the air cleaner element with
oil. Squeeze out excess oil.
(cont’d)
17CRF450X31MEY710.indb51 2016/06/0811:45:42
52 Servicing Your Honda
NOTICE
Improper installation of the air cleaner element
assembly may allow dirt and dust to enter the
engine and cause rapid wear of the piston rings
and cylinder.
12. Close the air cleaner housing cover (1) and
turn the quick fastener (2) clockwise.
(2)
(1)
(1) air cleaner housing cover
(2) quick fast
ener
8. Assemble the air cleaner element and holder.
Install the tab (7) of the holder in the hole (8)
of the air cleaner element tab (9).
9. Apply 0.05 – 0.19 oz (1.5 – 5.5 g) of Pro
Honda White Lithium Grease or equivalent to
the air cleaner housing contact area of the air
cleaner element.
10. Install the air cleaner element assembly into
the air cleaner housing.
11. Carefully position the sealing flange of the
element to prevent dirt intrusion.
Align the access tab (10) of the air cleaner
element holder with the “
” mark (11) of the
air cleaner housing by rotating the air cleaner
element assembly counterclockwise. Install
and tighten the air cleaner element retaining
bolt (3) securely.
(10)
(11)
(3)
(3) air cleaner element retaining bolt
(10) access tab
(1
1) “
” mark
Air Cleaner
17CRF450X31MEY710.indb52 2016/06/0811:45:42
Servicing Your Honda 53
Crankcase Breather
Refer to Safety Precautions on page 25.
Service more frequently if your CRF is ridden in
the rain or often at full throttle.
Service the breather if you can see deposits in the
transparent section of the drain tube.
Draining
1. Remove the crankcase breather tube plug (1)
from the tube (2) and drain the deposits into a
suitable container.
2. Reinstall the crankcase breather tube plug.
(1)
(2)
(1) crankcase breather tube plug
(2) tube
17CRF450X31MEY710.indb53 2016/06/0811:45:42
54 Servicing Your Honda
Lower Adjustment
The lower adjuster is used for major freeplay
adjustment, such as after replacing the throttle
cables or removing the carburetor. It is also used
if you can not get the proper adjustment with the
upper adjuster.
(5)
(6)
(+)
(–)
(5) lower lock nut (+) increase
(6) lower adjust
er (–) decrease
1. Remove the seat and fuel tank (pages 36, 37).
2. Loosen the lower lock nut (5).
3. Turn the lower adjuster (6) in direction (–)
to decrease freeplay, and in direction (+) to
increase freeplay.
4. Tighten the lock nut to the specified torque:
3.0 lbf·ft (4 N·m, 0.4 kgf·m)
Operate the throttle grip to ensure that it
functions smoothly and returns completely.
5. Install the fuel tank and seat (pages 36, 38).
If you can’t get the freeplay within the specified
range, see your dealer.
Throttle
Refer to Safety Precautions on page 25.
Throttle Freeplay
(1)
(1) freeplay
Inspection
Check freeplay (1).
Freeplay: 1/8 – 3/16 in (3 – 5 mm)
If necessary, adjust to the specified range.
Upper Adjustment
Minor adjustments are generally made with the
upper adjuster.
(2)
(+)
(–)
(3)
(4)
(2) dust cover (+) increase
(3) upper lock nut
(–) decrease
(4) upper adjuster
1. Pull the dust cover (2) back.
2. Loosen the upper lock nut (3).
3. Turn the upper adjuster (4).
Turning the adjuster in direction (–) will
decrease freeplay and turning it in direction
(+) will increase freeplay.
4. Tighten the lock nut to the specified torque:
3.0 lbf·ft (4 N·m, 0.4 kgf·m)
Return the dust cover to its normal position.
5. After adjustment, check for smooth rotation
of the throttle grip from fully closed to fully
open in all steering positions.
If the adjuster is threaded out near its limit or
the correct freeplay cannot be reached, turn
the adjuster all the way in and back out one
turn.
Tighten the lock nut to the specified torque:
3.0 lbf·ft (4 N·m, 0.4 kgf·m)
Return the dust cover and make the
adjustment with the lower adjuster.
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Servicing Your Honda 55
Throttle
Throttle Inspection
(1)
(1) throttle
1. Check that the throttle assembly is positioned
properly and the securing bolts are tight.
2. Check for smooth rotation of the throttle (1)
from fully open to fully closed in all steering
positions. If there is a problem, see your
dealer.
3. Inspect the condition of the throttle cables
from the throttle grip down to the carburetor.
If the cable is kinked or chafed, have it
replaced.
4. Check the cables for tension or stress in all
steering positions.
5. Lubricate the cables with a commercially
available cable lubricant to prevent premature
rust and corrosion.
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56 Servicing Your Honda
Clutch System
Refer to Safety Precautions on page 25.
Clutch Lever Freeplay
(1)
(1) clutch lever
Inspection
Check freeplay.
Freeplay: 3/8 – 13/16 in (10 – 20 mm)
If necessary, adjust to the specified range.
Improper freeplay adjustment can cause
premature clutch wear.
Make sure to adjust the clutch lever (1) freeplay
after the clutch cable is disconnected.
Cable End Adjustment
Minor adjustments are generally made with the
clutch cable end adjuster.
(–)
(+)
(1)
(1) cable end adjuster
(+) increase freepla
y
(–) decrease freeplay
Turning the cable end adjuster (1) in direction (+)
will increase freeplay and turning it in direction
( –) will decrease freeplay.
If the adjuster is threaded out near its limit or
the correct freeplay cannot be reached, turn the
adjuster all the way in and back out one turn
and make the adjustment with the integral cable
adjuster.
Integral Cable Adjustment
The integral cable adjuster is used if the cable
end adjuster is threaded out near its limit or the
correct freeplay cannot be obtained.
(–)
(+)
(1)
(2)
(1) lock nut (+) increase
(2) integral cable adjuster (–) decrease
1. Turn the cable end adjuster in direction (+)
until it seats lightly and then turn it out five
turns.
2. Loosen the lock nut (1).
3. Turn the integral cable adjuster (2) to obtain
the specified freeplay.
4. Tighten the lock nut. Check the freeplay.
5. Start the engine, pull the clutch lever in, and
shift into gear. Make sure the engine does
not stall and the motorcycle does not creep.
Gradually release the clutch lever and open
the throttle. Your CRF should move smoothly
and accelerate gradually.
If you can’t get proper adjustment, or the clutch
does not work properly, the cable may be kinked
or worn, or the clutch discs may be worn.
Inspect the clutch discs and plates (page 58).
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Servicing Your Honda 57
Clutch System
Other Inspections & Lubrication
• Check that the clutch lever assembly is
positioned properly (the end of the holder
(1) is aligned with the paint mark (2) on the
handlebar) and the securing bolts are tight.
(1)
(2)
(1) holder
(2) paint mark
• Check the clutch cable for kinks or signs of
wear. If necessary, have it replaced.
• Lubricate the clutch cable with a
commercially-available cable lubricant to
prevent premature wear and corrosion.
Clutch Operation
1. Check for smooth clutch lever operation. If
necessary, lubricate the clutch lever pivot or
clutch cable.
2. Check the clutch cable for deterioration,
kinks, or damage.
3. Remove the six clutch cover bolts (6) and
clutch cover (7).
(7)
(6)
(6) clutch cover bolts
(7) clutch cover
4. Remove the six clutch spring bolts and clutch
springs (8).
Loosen the clutch spring bolts in a crisscross
pattern in two or three progressive steps.
5. Remove the clutch pressure plate (9).
(8)
(9)
(8) clutch spring bolts/clutch springs
(9) clutch pressure plate
(cont’d)
Clutch Cover/Disc/Plate Removal
1. Drain the transmission oil (page 47).
2. Remove the rear brake pedal (1) by removing
the pin (2), pivot bolt (3), washer (4) and dust
seals (5).
(2)
(4)
(5)
(3)
(1)
(1) rear brake pedal (4) washer
(2) pin (5) dust seals
(3) pivot bolt
17CRF450X31MEY710.indb57 2016/06/0811:45:44
58 Servicing Your Honda
Clutch System
Clutch Disc/Plate Inspection
Replace the clutch discs (1) if they show signs of
scoring or discoloration.
Measure the thickness of each clutch disc.
Service Limit: 0.112 in (2.85 mm)
Replace the clutch discs and clutch plates as a
set.
(1)
(1) clutch disc
Check the clutch plates (2) for excessive warpage
or discoloration.
Check the plate warpage on a surface plate using
a feeler gauge.
Service Limit: 0.006 in (0.15 mm)
Replace the clutch discs and clutch plates as a
set
.
(2)
(2) clutch plate
Clutch Spring Inspection
(1)
(1) clutch spring
Measure the free length of each spring.
Service Limit: 1.72 in (43.7 mm)
Replace the clutch springs as a set if any one of
them is below the service limit or if the clutch
plates have been burnt/heat discolored.
6. Remove the washer (10), needle bearing (11),
clutch lifter (12) and clutch lifter rod (13).
7. Remove the eight clutch discs and seven
clutch plates (14).
Assemble the clutch lifter, needle bearing
and washer. Turn the needle bearing with
your finger. The needle bearing should turn
smoothly and quietly. Replace the needle
bearing and washer if the needle bearing does
not turn smoothly.
(11)
(12) (13)
(14)
(10)
(10) washer
(11) needle bearing
(1
2) clutch lifter
(13) clutch lifter rod
(14) clutch discs/clutch plates
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Servicing Your Honda 59
Clutch System
12. Lubricate the dust seals (12), rear brake pedal
(13) pivot and pivot bolt (14) with Pro Honda
White Lithium Grease or equivalent.
13. Install the dust seals into the rear brake pedal.
14. Install the pivot bolt with the washer (15) and
tighten the pivot bolt to the specified torque:
27 lbf·ft (36 N·m, 3.7 kgf·m)
Connect the brake pedal return spring (16) if
it is removed.
15. Insert the pin (17).
(16)
(17)
(15)
(14)
(13)
(12)
(12) dust seals (15) washer
(13) rear br
ake pedal (16) brake pedal return spring
(14) pivot bolt (17) pin
16. Fill the crankcase with transmission oil (page
47).
Clutch Disc/Plate Installation
1. Coat the clutch disc A (1), B (2) and plates
(3) with engine oil.
2. Starting and ending with the two clutch disc
A, alternately install the six clutch disc B and
seven clutch plates.
(3)
(2)
(
1)
(1)
(2)(1)
(1) clutch disc A
(2) clutch disc B
(3) clutch plates
3. Apply grease to the clutch lifter rod (4).
4. Insert the clutch lifter rod into the mainshaft.
5. Apply engine oil to the needle bearing (5) and
washer (6) and install them to the clutch lifter
(7).
6. Install the clutch lifter onto the rod.
(6) (5) (7) (4)
(4) clutch lifter rod (6) washer
(5) needle bearing (7) clutch lif
ter
7. Install the clutch pressure plate (8).
8. Install the six clutch springs and bolts (9).
9. Tighten the bolts in a crisscross pattern in
two or three steps, to the specified torque:
9 lbf·ft (12 N·m, 1.2 kgf·m)
(9)
(8)
(8) clutch pressure plate
(9) clutch spring bolts/springs
10. Apply oil to a new O-ring (10) and install it
in the groove of the clutch cover (11).
11. Install the clutch cover by tightening the six
clutch cover bolts in a crisscross pattern in
two or three steps to the specified torque:
7 lbf·ft (10 N·m, 1.0 kgf·m)
(10)
(11)
(10) O-ring
(11) clutch cov
er
17CRF450X31MEY710.indb59 2016/06/0811:45:46
60 Servicing Your Honda
Hot Start Lever
Refer to Safety Precautions on page 25.
Hot Start Lever Freeplay
(1)
(2)
(1) hot start lever
(2) freeplay
Inspection
Check freeplay (2).
Freeplay: 1/16 – 1/8 in (2 – 3 mm)
If necessary, adjust to the specified range.
Adjustment
Adjustments can be made with the cable end
adjuster.
Loosen the lock nut (1) and turn the adjuster (2).
Turning the adjuster clockwise (+) will increase
freeplay and turning it counterclockwise (–) will
decrease freeplay. After adjustment, tighten the
lock nut.
(+)
(–)
(2)
(1)
(1) lock nut (+) increase
(2) adjuster
(–) decrease
17CRF450X31MEY710.indb60 2016/06/0811:45:46
Servicing Your Honda 61
Refer to Safety Precautions on page 25.
Spark Plug Recommendation
The recommended standard spark plug is
satisfactory for most racing conditions.
Standard IFR8H11
VK24PRZ11
(NGK) or
(DENSO)
Optional IFR9H11
VK27PRZ11
(NGK) or
(DENSO)
Use only the recommended type of spark plugs in
the recommended heat range.
NOTICE
Using a spark plug with an improper heat range
or incorrect reach can cause engine damage.
Using a non-resistor spark plug may cause
ignition problems.
This motorcycle uses a spark plug that has an
iridium tip in the center electrode and a platinum
tip in the side electrode.
Be sure to observe the following when servicing
the spark plug.
• Do not clean the spark plug. If an electrode
is contaminated with accumulated objects or
dirt, replace the spark plug with a new one.
• To check the spark plug gap, use only a “wire-
type feeler gauge.” To prevent damaging
the iridium tip of the center electrode and
platinum tip of the side electrode, never use a
“leaf-type feeler gauge.’’
• Do not adjust the spark plug gap. If the gap
is out of specification, replace the spark plug
with a new one.
Spark Plug
Spark Plug Inspection & Replacement
1. Remove the seat and fuel tank (pages 36, 37).
2. Disconnect the spark plug cap (1).
3. Clean any dirt from around the spark plug base.
4. Remove the spark plug (2).
(1)
(2)
(1) spark plug cap
(2) spark plug
5. Check the electrodes for wear or deposits,
the sealing gasket (3) for damage, and the
insulator for cracks. Replace if you detect
them.
6. Check the spark plug gap (4), using a
wire-type feeler gauge. If the gap is out of
specifications, replace the plug with a new
one.
The recommended spark plug gap is:
0.039 – 0.043 in (1.0 – 1.1 mm)
(3) sealing gasket
(4) spark plug gap
(3)
(4)
7. To obtain accurate spark plug readings,
accelerate up to speed on a straightaway.
Push the engine stop button and disengage
the clutch by pulling the lever in.
Coast to a stop, then remove and inspect the
spark plug. The porcelain insulator around
the center electrode should appear tan or
medium gray.
If you’re using a new plug, ride for at least 10
minutes before taking a plug reading; a brand-
new plug will not color initially.
If the electrodes appear burnt, or the insulator is
white or light gray (lean) or the electrodes and
insulator are black or fouled (rich), there is a
problem elsewhere.
Check the carburetor, fuel system and ignition
timing.
8. With the sealing gasket attached, thread
the spark plug in by hand to prevent cross-
threading.
9. Tighten the spark plug:
• If the old plug is good:
1/8 turn after it seats.
• If installing a new plug, tighten it twice to
prevent loosening:
a) First, tighten the plug:
NGK: 3/4 turn after it seats.
DENSO: 1/2 turn after it seats.
b) Then loosen the plug.
c) Next, tighten the plug again:
1/8 turn after it seats.
NOTICE
An improperly tightened spark plug can damage
the engine. If a plug is too loose, a piston may be
damaged. If a plug is too tight, the threads may
be damaged.
10. Connect the spark plug cap. Take care to
avoid pinching any cables or wires.
11. Install the fuel tank and seat (pages 36, 38).
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62 Servicing Your Honda
Exhaust Pipe/Muffler
Exhaust Pipe/Muffler Inspection
Check the mounting bolts and exhaust pipe joint
nuts for tightness.
Check the exhaust pipe and muffler for cracks or
deformation.
A damaged exhaust pipe and muffler may reduce
engine performance.
2. Loosen the muffler clamp bolt (4).
3. Remove the rear muffler mounting bolt/
washer (5), front muffler mounting bolt (6)
and muffler (7).
(4)
(7)
(6)
(5)
(4) muffler clamp bolt
(5) rear muf
fler mounting bolt/washer
(6) front muffler mounting bolt
(7) muffler
Muffler Removal
1. Remove the seat mounting bolt (1), side
cover bolt (2) and right side cover (3).
(1)
(3)
(2)
(1) seat mounting bolt
(2) side cover bolt
(3) r
ight side cover
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Servicing Your Honda 63
Exhaust Pipe/Muffler
5. Install the front muffler mounting bolt (7),
rear muffler mounting bolt/washer (8) and
loosely tighten them.
Tighten the front muffler mounting bolt and
rear muffler mounting bolt to the specified
torque:
19 lbf·ft (26 N·m, 2.7 kgf·m)
6. Tighten the muffler clamp bolt (9) to the
specified torque:
15 lbf·ft (21 N·m, 2.1 kgf·m)
(7)
(8)
(9)
(7) front muffler mounting bolt
(8) rear muf
fler mounting bolt/washer
(9) muffler clamp bolt
7. Install the right side cover (10) and side cover
bolt (11).
8. Install the seat mounting bolt (12) and tighten
it to the specified torque:
19 lbf·ft (26 N·m, 2.7 kgf·m)
(12)
(10)
(11)
(10) right side cover
(11) side cov
er bolt
(12) seat mounting bolt
Muffler Installation
1. Remove the gasket (1).
2. Install the muffler clamp (2) and a new gasket
onto the exhaust pipe (3).
(1)
(3)
(2)
(1) gasket
(2) muff
ler clamp
(3) exhaust pipe
3. Install the muffler (4).
4. Install the muffler clamp (2) by aligning the
tab (5) of the muffler clamp with the cut-out
(6) of the muffler.
(4)
(2)
(5)
(6)
(2) muffler clamp (5) tab
(4) muff
ler (6) cut-out
17CRF450X31MEY710.indb63 2016/06/0811:45:47
64 Servicing Your Honda
Exhaust Pipe/Muffler
Exhaust Pipe Installation
1. Install a new exhaust pipe gasket (1) as
shown.
2. Install the exhaust pipe (2) and exhaust pipe
joint nuts (3).
(1)
(2)
(3)
(1) new exhaust pipe gasket
(2) exhaust pipe
(3) exhaust pipe joint n
uts
3. Install the muffler (page 63) but do not
tighten the bolts yet.
4. Tighten the exhaust pipe joint nuts to the
specified torque:
15 lbf·ft (21 N·m, 2.1 kgf·m)
5. Tighten the muffler clamp bolt, front muffler
mounting bolt and rear muffler mounting bolt
(page 63).
6. Installation can be done in the reverse order
of removal.
Exhaust Pipe Removal
1. Remove the muffler (page 62).
2. Remove the exhaust pipe joint nuts (1),
exhaust pipe (2) and old exhaust pipe gasket
(3).
(2)
(1)
(3)
(1) exhaust pipe joint nuts
(2) exhaust pipe
(3) old exhaust pipe g
asket
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Servicing Your Honda 65
Spark Arrester
3. Use a brush to remove carbon deposits from
the spark arrester screen. Be careful to avoid
damaging the spark arrester screen. The spark
arrester must be free of breaks and holes.
Replace, if necessary.
4. Apply a seizure inhibitor (Three Bond 1901
or equivalent) to the bolts threads.
5. Install a new gasket and the spark arrester in
the muffler and tighten the bolts (1) to the
specified torque:
4.4 lbf·ft (6 N·m, 0.6 kgf·m)
(1)
(1) bolts
Spark Arrester Inspection
The spark arrester must be serviced every 1,000
miles (1,600 km) of running or 100 operating
hours to maintain its efficiency.
Regular servicing prevents carbon buildup
(which can diminish engine performance) and
also complies with USDA regulations for regular
maintenance to assure proper function.
The spark arrester prevents random sparks from
the combustion process in your engine from
reaching the environment.
1. Allow the engine and muffler to cool.
2. Remove the bolts (1), spark arrester (2), and
gasket (3) from the muffler.
(1)
(2)
(3)
(1) bolts (3) gasket
(2) spark arrest
er
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66 Servicing Your Honda
Valve Clearance
Cylinder Head Cover Removal
Before inspection, clean the engine thoroughly to
keep dirt from entering the engine.
1. Remove the seat and fuel tank (pages 36, 37).
2. Disconnect the breather tube (1) and spark
plug cap (2).
(1)
(2)
(1) breather tube
(2) spark plug cap
3. Remove the spark plug (page 61).
4. Remove the cylinder head cover A bolt/
rubber seal (3), cylinder head cover B bolts/
rubber seals (4) and cylinder head cover (5).
(5)
(4)
(3)
(3) cylinder head cover A bolt/rubber seal
(4) cylinder head cov
er B bolts/rubber seals
(5) cylinder head cover
Refer to Safety Precautions on page 25.
Excessive valve clearance will cause noise and
eventual engine damage. Little or no clearance
will prevent the valve from closing and cause
valve damage and power loss. Check the valve
clearance when the engine is cold at the intervals
specified in the Maintenance Schedule (pages 27,
28).
The checking or adjusting of the valve clearance
should be performed while the engine is cold.
The valve clearance will change as engine
temperature rises.
5. Remove the plug hole packing and cylinder
head cover packing.
Positioning At Top Dead Center On The
Compression Stroke
1. Remove the crankshaft hole cap (1).
(1)
(1) crankshaft hole cap
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Servicing Your Honda 67
Valve Clearance
(5)
(5) exhaust rocker arm
Valve Clearance Inspection
1. Measure the intake valve clearance by
inserting a feeler gauge (1) between the valve
lifters (2) and intake cam lobes (3).
(1)
(3)
(2)
(1) feeler gauge
(2) valve lifters
(3) intake cam lobes
Valve Clearance:
IN: 0.006 ± 0.001 in (0.16 ± 0.03 mm)
2. Measure the exhaust valve clearance by
inserting a feeler gauge (1) between the
exhaust rocker arm (4) and shims (5).
(4)
(1)
(5)
(1) feeler gauge
(4) exhaust rocker arm
(5) exhaust valve shims
Valve Clearance:
EX: 0.011 ± 0.001 in (0.28 ± 0.03 mm)
If intake valve clearance and exhaust valve
clearance need adjustment, see Camshaft Holder
Assembly Removal (page 68) and select the
correct shim for each valve.
2. Rotate the crankshaft by turning the primary
drive gear bolt (2) clockwise until the
punch mark (3) on the primary drive gear
aligns with the index mark (4) on the right
crankcase cover. In this position, the piston
may either be on the compression or exhaust
stroke. If the crankshaft passed the punch
mark, rotate the primary drive gear bolt
clockwise again and align the punch mark
with the index mark.
The inspection must be made when the piston
is at the top of the compression stroke when
both the intake and exhaust valves are closed.
This condition can be determined by moving
the exhaust rocker arm (5). If it is free, it is
an indication that the valves are closed and
that the piston is on the compression stroke.
If it is tight and the valves are open, rotate the
primary drive gear bolt 360° and realign the
punch mark with the index mark.
(2)
(4)
(3)
(2) primary drive gear bolt
(3) punch mar
k
(4) inde
x mar
k
17CRF450X31MEY710.indb67 2016/06/0811:45:49
68 Servicing Your Honda
Valve Clearance
Camshaft Holder Assembly Removal
1. Record the intake valve and exhaust valve
clearances.
Make sure the piston is at TDC (Top Dead
Center) on the compression stroke (page 66).
2. Remove the cam chain tensioner lifter cover
bolt (1) and sealing washer (2).
(2)
(1)
(1) cam chain tensioner lifter cover bolt
(2) sealing washer
Use the tensioner stopper tool.
• Tensioner stopper 07AMG-001A100
3. Turn the tensioner shaft clockwise with the
tensioner stopper (3) until it stops, in order to
retract the tensioner fully.
Then insert the tensioner stopper fully to hold
the stopper in the fully retracted position.
(3)
(3) tensioner stopper
4. Loosen the cam sprocket bolt (4).
Rotate the primary drive gear bolt
(crankshaft) clockwise one turn and remove
the other sprocket bolt. Rotate the primary
drive gear bolt (crankshaft) clockwise one
turn again and remove the remaining sprocket
bolt.
5. Remove the cam sprocket (5) and then
attach a piece of wire to the cam chain (6) to
prevent it from falling into the crankcase.
NOTICE
Do not let the bolts, sprocket and cam chain fall
into the crankcase.
(6)
(5)
(4)
(4) cam sprocket bolts
(5) cam sprocket
(6) cam chain
17CRF450X31MEY710.indb68 2016/06/0811:45:50
Servicing Your Honda 69
Valve Clearance
6. Make sure the piston is at TDC (Top Dead
Center) on the compression stroke.
Loosen the camshaft holder assembly bolts
(7) in a crisscross pattern in two or three
steps.
Remove the camshaft holder assembly bolts,
camshaft holder assembly (8), intake valve
lifters and shims.
• As you remove the camshaft holder assembly,
the intake valve lifters and intake valve
shims may be sticking in the camshaft holder
assembly.
• Keep the intake valve lifters and the shims
separate so you can easily identify the
originally installed location such as intake or
exhaust, right or left.
(8)
(7)
(7) camshaft holder assembly bolts
(8) camshaft holder assembl
y
NOTICE
Do not let the valve lifters, shims, decompressor
shaft and plunger fall into the crankcase.
7. Remove the intake valve lifters (9),
decompressor shaft (10) and plunger (11).
(9)
(10)
(11)
(9) intake valve lifters
(10) decompressor shaf
t
(11) plunger
8. Remove the valve shims (12).
(12)
(12) valve shims
17CRF450X31MEY710.indb69 2016/06/0811:45:51
70 Servicing Your Honda
Valve Clearance
Shim Selection
1. Clean the shim contact area in the valve lifter
(1) with compressed air.
(1)
(1) valve lifter
2. Measure the shim thickness with a
micrometer and record it.
Seventy-three different thickness shims (2)
are available from the thinnest (1.200 mm
thickness) shim to the thickest (3.000 mm
thickness) in intervals of 0.025 mm.
(2)
(2) shim
3. Calculate the new shim thickness using the
equation below.
A = (B – C) + D
A: New shim thickness
B: Recorded valve clearance
C: Specified valve clearance
D: Old shim thickness
• Make sure of the correct shim thickness by
measuring the shim with a micrometer.
• Reface the intake valve seat if carbon deposits
result in a calculated dimension of over
2.450 mm.
Reface the exhaust valve seat if carbon
deposits result in a calculated dimension of
over 3.000 mm.
180
1.80 mm 1.825 mm 1.85 mm 1.875 mm
182 185 188
17CRF450X31MEY710.indb70 2016/06/0811:45:51
Servicing Your Honda 71
Valve Clearance
(cont’d)
Camshaft Holder Assembly Installation
1. Install the newly selected shims (1) on the
valve spring retainers (2).
NOTICE
Do not let the shims fall into the crankcase.
(2)
(1)
(2)
(1)
(1) shims
(2) valv
e spring retainers
2. Apply molybdenum disulfide oil (a mixture
of 1/2 engine oil and 1/2 molybdenum
disulfide grease containing more than 3%
molybdenum disulfide additive) to the
following parts.
– camshaft cam lobes
– each valve lifter outer surface
– plunger whole surface
– decompressor shaft sliding area
5. Install the camshaft holder assembly (9) onto
the cylinder head with the intake cam lobes
(10) facing up as illustrated below.
Apply engine oil to the camshaft holder
assembly bolt threads and seating surface.
Tighten the camshaft holder assembly bolts
(11) to the specified torque:
10 lbf·ft (14 N·m, 1.4 kgf·m)
NOTICE
Do not let the decompressor shaft and plunger
fall into the crankcase.
Tighten the camshaft holder assembly bolts in a
crisscross pattern in two or three steps.
(9)
(11)
Exhaust side
(10)
(9) camshaft holder assembl
y
(10) intake cam lobes
(11) camshaft holder assembly bolts
3. Install the plunger (3) into the camshaft (4)
with its rounded surface facing up and groove
(5) side toward the decompressor shaft (6).
Install the decompressor shaft while aligning
its tab (7) with the groove of the plunger
shown.
Check the operation of the plunger by turning
the decompressor shaft with your finger,
then pushing down and pull up the plunger
smoothly.
(7)
(6)
(6)
(4)
(5)
Align
(3)
(3) plunger (6) decompressor shaft
(4) camshaft (7) tab
(5) groove
4. Install the each valve lifter (8) in their
original location into the camshaft holder
assembly (9).
(8)
(9)
(8) valve lifters
(9) camshaft holder assembl
y
17CRF450X31MEY710.indb71 2016/06/0811:45:52
72 Servicing Your Honda
Valve Clearance
6. While holding the cam chain, rotate the
primary drive gear bolt (12) (crankshaft)
clockwise and align the punch mark (13) with
the index mark (14).
Make sure the piston is at TDC (Top Dead
Center) on the compression stroke.
(12)
(14)
(13)
(12) primary drive gear bolt
(13) punch mark
(1
4) index mark
7. Install the cam chain (15) over the sprocket
without rotating the sprocket.
Place the cam sprocket (16) and align the
timing mark (17) on the cam sprocket with
the “
” mark (18) on the camshaft holder
assembly.
When installing the cam sprocket, position
the decompressor weight pin (19) toward the
front side.
8. Set the decompressor weight (20) by aligning
its hole (21) with out side weight pin (22) as
shown.
(15)
(19)
(22)
(21)
(20)
(16)
(18)
(17)
(15) cam chain (19) decompressor weight pin
(16) cam sproc
ket (20) decompressor weight
(17) timing mark (21) hole
(18) “
” mark (22) out side weight pin
9. Clean and apply a locking agent to the cam
sprocket bolt (25) threads (coating width as
shown).
(23) 0.26 ± 0.04 in
(6.5 ± 1.0 mm)
(24) 0.04 – 0.08 in
(1.0 – 2.0 mm)
(25)
(23) coating width
(24) no coating width
(25) cam sprock
et bolt
10. Temporarily install the cam sprocket bolt (25)
by aligning the bolt holes of the cam sprocket
and camshaft.
Rotate the primary drive gear bolt
(crankshaft) clockwise one turn and tighten
the sprocket bolt to the specified torque:
15 lbf·ft (20 N·m, 2.0 kgf·m)
Rotate the primary drive gear bolt
(crankshaft) clockwise one turn again and
tighten the other sprocket bolt to the specified
torque (see above).
NOTICE
Do not let the bolts fall into the crankcase.
(25)
(25) cam sprocket bolts
17CRF450X31MEY710.indb72 2016/06/0811:45:53
Servicing Your Honda 73
Valve Clearance
13. Rotate the primary drive gear bolt
(crankshaft) clockwise two turns and align
the punch mark (13) with the index mark
(14). Make sure that the timing mark (17)
on the sprocket align with the “
” mark
(18) on the camshaft holder assembly. If the
timing mark doesn’t align with the “
” mark,
remove the cam sprocket.
Then realign the valve timing.
(13) (14)
(17)
(18)
(13) punch mark
(14) index mar
k
(17) timing mark
(18) “
” mark
14. Measure the intake valve and exhaust valve
clearances by inserting a feeler gauge (27).
Valve Clearance:
IN: 0.006 ± 0.001 in (0.16 ± 0.03 mm)
EX: 0.011 ± 0.001 in (0.28 ± 0.03 mm)
(27)
(27)
(27) feeler gauge
15. Install a new sealing washer (28) and tighten
the cam chain tensioner lifter cover bolt (29).
(28)
(29)
(28) sealing washer
(29) cam chain tensioner lift
er cover bolt
11. Check the operation of the plunger (3) by
pushing the decompressor weight (20) with
your finger and then pushing the plunger
down. Release the decompressor weight and
pull up the plunger.
(3)
(20)
(3) plunger
(20) decompressor weight
12. Remove the tensioner stopper (26) from the
cam chain tensioner lifter.
(26)
(26) tensioner stopper
17CRF450X31MEY710.indb73 2016/06/0811:45:53
74 Servicing Your Honda
Valve Clearance
Crankshaft Hole Cap Installation
Coat a new O-ring (1) with engine oil and install
it onto the crankshaft hole cap (2).
Apply grease to the crankshaft hole cap threads.
Install and tighten the crankshaft hole cap to the
specified torque:
11 lbf·ft (15 N·m, 1.5 kgf·m)
(1)
(2)
(1) O-ring
(2) crankshaft hole cap
Cylinder Head Cover Installation
1. Check the spark plug hole packing (1) is in
good condition, replace it if necessary.
Apply engine oil to the spark plug hole
packing and install it to the spark plug hole
(2).
(1)
(2)
(1) spark plug hole packing
(2) spark plug hole
2. Inspect the cylinder head cover packing (3)
for damage or deterioration, replace it if
necessary.
Install the cylinder head cover packing into
the groove of the cylinder head cover (4).
(4)
(3)
(3) cylinder head cover packing
(4) cylinder head cov
er
3. Check the rubber seals (5) are in good
condition, replace them if necessary.
Install the rubber seals onto the cylinder head
cover with the “UP” marks (6) facing up.
(6)
(6)
(5)
(5) rubber seal
(6) “UP” mar
ks
4. Install the cylinder head cover (4).
5. Tighten the cylinder head cover A bolt/rubber
seal (7) and cylinder head cover B bolts/
rubber seals (8) to the specified torque:
7 lbf·ft (10 N·m, 1.0 kgf·m)
(4)
(8)
(7)
(4) cylinder head cover
(7) cylinder head cover A bolt/rubber seal
(8) cylinder head cover B bolts/rubber seals
17CRF450X31MEY710.indb74 2016/06/0811:45:54
76 Servicing Your Honda
Piston/Piston Rings/Piston Pin
Cylinder Head Removal
1. Clean the area above the engine before
disassembly to prevent dirt falling into the
engine.
2. Drain the engine oil (page 44).
3. Drain the radiator coolant after cooling the
motorcycle (page 149).
4. Remove the seat and fuel tank (pages 36, 37).
5. Remove the muffler (page 62).
6. Lift the subframe to the upright position
(page 39).
7. Remove the carburetor (page 136).
8. Remove the exhaust pipe (page 64).
9. Remove the spark plug (page 61).
10. Remove the bolt A (1), bolt B (2) and O-ring
(3).
11. Disconnect the air suction hose (4) and
vacuum hose (5).
Remove the PAIR control valve (6).
(6)
(1)
(4)
(5)
(3)
(2)
(1) bolt A (4) air suction hose
(2) bolt B (5) vacuum hose
(3) O-r
ing (6) PAIR control valve
12. Remove the cylinder head cover (page 66).
13. Position the piston at top dead center on the
compression stroke (page 66).
14. Remove the camshaft holder assembly, lifters
and shims (page 68).
15. Remove the left radiator grill (7) and left
radiator mounting bolts/washers (8).
(7)
(8)
(7) left radiator grill
(8) left radiator mounting bolts/washers
16. Disconnect the primary wire connector (9).
Remove the bolt (10) and ignition coil (11).
(9)
(10)
(11)
(9) primary wire connector
(10) bolt
(11) ignition coil
17. Loosen the radiator hose clamp (12) and
disconnect the radiator hose (13).
(13)
(12)
(12) radiator hose clamp
(13) radiat
or hose
17CRF450X31MEY710.indb76 2016/06/0811:45:56
Servicing Your Honda 77
Piston/Piston Rings/Piston Pin
22. Remove the dowel pins (25), cylinder head
gasket (26) and cam chain guide (27).
NOTICE
Do not let the dowel pins and cam chain fall into
the crankcase.
(27)
(26)
(25)
(25) dowel pins
(26) cylinder head gasket
(27) cam chain guide
18. Remove the engine hanger nut (14), engine
hanger bolt (15) and fuel hose guide (16).
Remove the engine hanger plate bolts (17),
clutch cable stay (18), left engine hanger
plate (19) and right engine hanger plate (20).
(14)
(18)
(17)
(20)
(17)
(19)
(16)
(15)
(14) engine hanger nut
(15) engine hanger bolt
(16) fuel hose guide
(17) engine hanger plate bolts
(18) clutch cable stay
(19) left engine hanger plate
(20) right engine hanger plate
19. Remove the cylinder head bolts (21).
20. Loosen the cylinder bolt (22).
(22)
(21)
(21) cylinder head bolts
(22) cylinder bolt
21. Remove the cylinder head nuts/washers (23)
and cylinder head (24).
Loosen the nuts in a criss-cross pattern in two or
three steps.
NOTICE
Do not let the nuts, washers and cam chain fall
into the crankcase.
(23)
(24)
(23) cylinder head nuts/washers
(24) cylinder head
17CRF450X31MEY710.indb77 2016/06/0811:45:56
78 Servicing Your Honda
Piston/Piston Rings/Piston Pin
Cylinder Removal
1. Disconnect the breather hose (1) from the
cylinder.
2. Remove the cylinder bolt (2) and cylinder (3).
NOTICE
Do not let the cam chain fall into the crankcase.
Do not pry on or strike the cylinder.
(1)
(3)
(2)
(1) breather hose (3) cylinder
(2) cylinder bolt
3. Remove the dowel pins (4) and cylinder
gasket (5).
NOTICE
Do not let the dowel pins fall into the crankcase.
(4)
(5)
(4) dowel pins
(5) cylinder gasket
Piston Ring Removal
Spread each piston ring (1) and remove by lifting
it up at a point just opposite the gap.
NOTICE
Do not damage the piston ring by spreading the
ends too far.
(1)
(1) piston ring
Piston Removal
1. Place clean shop towels in the crankcase to
keep the piston pin clips, or other parts, from
falling into the crankcase.
2. Remove the piston pin clips (1) using a pair
of needle-nose pliers.
3. Press the piston pin (2) out of the piston (3),
and remove the piston.
Under racing conditions, the piston and rings
should be replaced after 15.0 hours of running.
Replace the piston pin after 30.0 hours of
running.
(1)
(3)
(2)
(1) piston pin clips
(2) piston pin
(3) piston
17CRF450X31MEY710.indb78 2016/06/0811:45:58
Servicing Your Honda 79
Piston/Piston Rings/Piston Pin
Piston Ring Installation
1. Remove the carbon deposits from the piston
head and piston ring grooves with the
removed ring (1).
(1)
(1) removed ring
2. Apply engine oil to each piston ring whole
surface and install them to the piston.
NOTICE
Do not damage the piston ring by spreading the
ends too far.
Do not damage the piston during piston ring
installation.
• To install the oil ring, install the spacer first,
then install the side rails.
• Install the top ring on the piston with the
marking side facing up.
3. After installing the rings they should rotate
freely, without sticking.
Space the ring end gaps 180 degrees apart
between top ring and upper side rail.
Space the ring end gaps 90 degrees apart
between upper side rail, spacer and lower
side rail.
top ring
oil ring
top ring
mark
side rail
oil
ring
side rail
spacer
piston
Piston/Piston Pin/Piston Ring Inspection
We recommend you consult the Service
Manual or your dealer for correct Service Limit
measurements.
17CRF450X31MEY710.indb79 2016/06/0811:45:59
80 Servicing Your Honda
Piston/Piston Rings/Piston Pin
Piston Installation
1. Place clean shop towels over the crankcase
opening to keep the piston pin clips from
falling into the crankcase.
2. Apply molybdenum disulfide oil (a mixture
of 1/2 engine oil and 1/2 molybdenum
disulfide grease containing more than 3%
molybdenum disulfide additive) to the
connecting rod small end inner surface.
3. Install the piston (1) with the “IN” mark (2)
and/or the large valve recesses (3) facing the
intake side of the engine.
4. Apply engine oil to the piston pin (4) outer
surface.
5. Apply engine oil to the piston outer surface
and piston pin hole inner surface.
Install the piston pin and new piston pin clips
(5).
NOTICE
Use new piston pin clips. Never reuse old piston
pin clips.
Do not let the piston pin clips fall into the
crankcase.
Do not align the piston pin clip end gap with the
piston cut-out (6).
Cylinder Installation
1. Clean off any gasket material from the gasket
surface of the crankcase, being careful not
to let any material fall into the crankcase.
Be careful not to remove any metal from the
gasket surface.
2. Remove the shop towel. Do not let any gasket
debris fall into the crankcase.
3. Install the dowel pins (1) and new cylinder
gasket (2).
NOTICE
Do not let the dowel pins fall into the crankcase.
(1)
(2)
(1) dowel pins
(2) cylinder gasket
4. Clean any gasket material off the cylinder.
(1)
(3)
(2)
(5)
(4)
(2)
(1)
(6)
(5)
(1) piston (4) piston pin
(2) “IN” mark (5) piston pin clips
(3) large valve recesses (6) piston cut-out
17CRF450X31MEY710.indb80 2016/06/0811:45:59
Servicing Your Honda 81
Piston/Piston Rings/Piston Pin
5. Apply engine oil to the cylinder wall, piston
outer surface and piston rings.
Route the cam chain (3) through the cylinder (4).
Install the cylinder over the piston rings by
hand while compressing the piston rings (5).
NOTICE
Do not damage the piston rings and cylinder
wall.
(4)
(3)
(5)
(3) cam chain
(4) cylinder
(5) piston r
ings
6. Temporarily install the cylinder bolt (6) and
connect the breather tube (7) to the cylinder.
(7)
(6)
(6) cylinder bolt
(7) breather tube
7. Install the cam chain guide (8) and fit the
cam chain guide tabs (9) in the cylinder cut-
outs (10).
Push the cam chain guide until it
bottoms in the crankcase guide hole.
(9)
(8)
(10)
(8) cam chain guide
(9) cam chain guide tabs
(1
0) cylinder cut-outs
Cylinder Head Installation
1. Install the dowel pins (1) and new cylinder
head gasket (2).
NOTICE
Do not let the dowel pins fall into the crankcase.
(2)
(1)
(1) dowel pins
(2) cylinder head gask
et
(cont’d)
17CRF450X31MEY710.indb81 2016/06/0811:45:59
82 Servicing Your Honda
Piston/Piston Rings/Piston Pin
2. Route the cam chain through the cylinder
head (3).
Install the cylinder head.
NOTICE
Do not damage mating surfaces when installing
the cylinder head.
3. Apply engine oil to all cylinder head nut
threads and seating surface.
Install the cylinder head nuts/washers (4) and
tighten them to the specified torque:
49 lbf·ft (66 N·m, 6.7 kgf·m)
NOTICE
Do not let the washers and nuts fall into the
crankcase.
Tighten the cylinder head nuts in a criss-cross
pattern in two or three steps.
(4)
(3)
(3) cylinder head
(4) cylinder head nuts/w
ashers
4. Install and tighten the cylinder bolt (5)
and cylinder head bolts (6) to the specified
torque:
7 lbf·ft (10 N·m, 1.0 kgf·m)
(6)
(5)
(5) cylinder bolt
(6) cylinder head bolts
5. Install the left engine hanger plate (7), right
engine hanger plate (8), clutch cable stay (9)
and engine hanger plate bolts (10) and tighten
the engine hanger plate bolts until the engine
hanger plates lightly contact the frame.
6. Install the engine hanger bolt (11), fuel hose
guide (12) and engine hanger nut (13) and
tighten the engine hanger nut until it lightly
contacts the engine hanger plates.
7. Tighten the engine hanger plate bolts to the
specified torque:
19 lbf·ft (26 N·m, 2.7 kgf·m)
Tighten the engine hanger nut to the specified
torque:
40 lbf·ft (54 N·m, 5.5 kgf·m)
(10)
(12)
(11)
(7)
(13)
(9)
(10)
(8)
(7) left engine hanger plate
(8) right engine hanger plat
e
(9) clutch cable stay
(10) engine hanger plate bolts
(11) engine hanger bolt
(12) fuel hose guide
(13) engine hanger nut
17CRF450X31MEY710.indb82 2016/06/0811:46:00
Servicing Your Honda 83
Piston/Piston Rings/Piston Pin
16. Connect the vacuum hose (24) and air suction
hose (25).
17. Install the PAIR control valve (26), new O-
ring (27) and tighten the bolt A (28), bolt B
(29).
(29)
(26)
(28)
(24)
(27)
(25)
(24) vacuum hose (27) O-ring
(25) air suction hose (28) bolt A
(26) P
AIR control valve (29) bolt B
18. Install the exhaust pipe (page 64).
19. Install the carburetor (page 139).
20. Install the subframe and muffler (pages 40, 63).
21. Install the fuel tank and seat (pages 36, 38).
22. Fill and bleed the cooling system (page 50).
23. Add engine oil (page 44).
Check for the following:
– compression leaks
– abnormal engine noise
– secondary air leaks
– coolant leaks
8. Connect the radiator hose (14) to the cylinder
head.
(14)
(14) radiator hose
9. Tighten the radiator hose clamp screw (15) as
illustrated below.
(15)
0 – 0.04 in
(0 – 1.0 mm)
(15) radiator hose clamp screw
10. Install the ignition coil (16), ground wire (17)
and bolt (18), then tighten the bolt.
Connect the primary wire connector (19).
Clamp the siphon hose (20) to the clamp (21).
(19)
(16)
(18)
(17)
(20)
(21)
(16) ignition coil (19) primary wire connector
(17) gr
ound wire (20) siphon hose
(18) bolt (21) clamp
11. Install and tighten the left radiator mounting
bolts/washers (22).
Install the left radiator grill (23).
(22)
(23)
(22) left radiator mounting bolts/washers
(23) left radiat
or grill
12. Install the camshaft holder assembly (page 71).
13. Install the crankshaft hole cap (page 74).
14. Install the cylinder head cover (page 74).
15. Install the spark plug and plug cap (page 61).
17CRF450X31MEY710.indb83 2016/06/0811:46:01
84 Servicing Your Honda
Suspension
Refer to Safety Precautions on page 25.
Loose, worn, or damaged suspension components
may adversely affect the handling and stability of
your CRF. If any suspension components appear
worn or damaged, see your dealer for further
inspection. Your dealer is qualified to determine
whether or not replacement parts or repairs are
needed.
Front Suspension Inspection
• When your CRF is new, break it in for
approximately 1 hour to ensure that the
suspension has worked in (page 21).
• After break-in, test run your CRF with the
front suspension at the standard setting before
attempting any adjustments.
• For optimum fork performance, we
recommend that you disassemble and clean
the fork after riding your CRF for 3 hours.
See page 113 for fork disassembly.
• Replace the fork oil every 7.5 hours of
running. See page 87 for oil capacity
adjustment after changing the fork oil.
• Replace the damper oil every 22.5 hours of
running. See page 117 for damper fork oil
replacement.
• Use Pro Honda HP Fork Oil 5W or an
equivalent which contains special additives to
assure maximum performance of your CRF’s
front suspension.
• Periodically check and clean all front
suspension parts to assure top performance.
Check the dust seals for dust, dirt, and
foreign materials. Check the oil for any
contamination.
• Refer to Suspension Adjustment Guidelines
(page 131). Make all rebound and
compression damping adjustments in one-
click increments. (Adjusting two or more
clicks at a time may cause you to pass over
the best adjustment.) Test ride after each
adjustment.
• If you become confused about adjustment
settings, return to the standard position and
start over.
• If the fork is still too stiff/soft after adjusting
compression damping, determine which
portion of the travel is still too stiff/soft. This
is an important step that will help you solve
suspension problems.
1. Make sure that the fork protectors (1) and
dust seals (2) are clean and not packed with
mud and dirt.
2. Check for signs of oil leakage. Damaged or
leaking fork seals should be replaced before
your CRF is ridden.
(2)
(1)
(1) fork protector (2) dust seal
3. Inspect the wear rings (3) for wear or
damage. Replace the wear ring if it is 0.08
in (2.0 mm) or flat with the outer tube (4).
When replacing the wear ring, remove the
fork leg (page 113). Install the wear ring with
its end gap (5) facing rearward.
(4)
(3)
0.08 in (2.0 mm)
(3) wear ring (4) outer tube
(3)
(5)
(3) wear rings (5) end gap
4. Make a quick check of fork operation by
locking the front brake and pushing down on
the handlebar several times.
17CRF450X31MEY710.indb84 2016/06/0811:46:01
Servicing Your Honda 85
Suspension
Rear Suspension Inspection
The swingarm is controlled by one hydraulic
shock absorber with an aluminum reservoir for
oil and nitrogen gas pressure. The gas pressure in
the reservoir is contained within a rubber bladder.
The shock absorber’s spring pre-load and
damping adjustments (compression and rebound)
should be adjusted for the rider’s weight and
track conditions (pages 130 – 133).
Do not attempt to disassemble, service, or
dis
pose of the damper; see your dealer. The
instructions found in this owner’s manual are
limited to adjustments of the shock assembly only.
• When your CRF is new, break it in for
approximately 1 hour with the standard
suspension settings before attempting to adjust
the rear suspension.
• Refer to Suspension Adjustment Guidelines
(page 133). Make all rebound and
compression damping adjustments in one
click or 1/12 turn increments.
(Adjusting two or more increments or turns
at a time may cause you to pass over the best
adjustment.) Test ride after each adjustment.
• If the rear suspension is too stiff/soft, adjust
it by turning all the compression and rebound
adjusters according to the procedures
described in page 127. After adjusting the
adjusters simultaneously, suspension may be
fine-tuned by turning one of the compression
and rebound damping adjusters in one click or
in 1/12 turn increments.
• If you have a problem finding an acceptable
adjustment, return to the standard position and
begin again.
1. Bounce the rear of the motorcycle up and
down and check for smooth suspension
action.
2. Lift the subframe to the upright position
(page 39).
3. Check for a broken or collapsed spring.
4. Check the shock absorber (1) for a bent rod
or oil leaks.
(1)
(1) shock absorber
5. Push the rear wheel sideways to check for
worn or loose swingarm bearings. There
should be no movement. If there is, have the
bearings replaced by your dealer.
17CRF450X31MEY710.indb85 2016/06/0811:46:02
86 Servicing Your Honda
Suspension
Recommended Fork Oil
viscosity (weight) 5 W
suggested oil Pro Honda HP Fork Oil or
equivalent
Fork Oil Change
Refer to Front Suspension Disassembly on page
113.
1. Clean the fork assembly, especially the
sliding surface of the slider and dust seal.
2. Record the rebound damping adjuster
position and turn the adjuster
counterclockwise until it stops.
3. Hold the outer tube (1), then remove the fork
damper (2) from the outer tube using the lock
nut wrench (3). Gently slide the outer tube
down onto the lower end of the slider (4).
(2)
(3)
(1)
(1)
(4)
(1) outer tube (3) lock nut wrench
(2) fork damper
(4) slider, lower end
NOTICE
The outer tube (1) can drop on the slider (5) and
damage the fork dust seal (6) and guide bushing
(7) when the fork damper is removed. To avoid
damage hold both the outer tube and slider when
removing the fork damper.
(6)
(7)
(5)
(1)
(1) outer tube (6) fork dust seal
(5) slider (7) guide bushing
4. Drain the fork oil from the outer tube (1).
Drain the fork oil from the oil holes (8) of the
fork damper.
(8)
(1)
(1) outer tube (8) oil holes
5. Drain the fork oil by turning the outer tube
(1) upside down. (About 0.4 US oz (12 cm
3
)
of fork oil will be left in the outer tube when
it is left inverted for about 20 minutes at 20
°C/68°F.)
(1)
(1) outer tube
Pour the drained oil into a suitable container and
dispose of it in an approved manner (page 151).
NOTICE
Improper disposal of drained oil is harmful to the
environment.
Amount of fork oil left in the fork
(within damper and spring) unit: cm
3
minute
°
C/
°
F
30/86
20/68
10/50
0/32
5
27
29.4
28.2
30.6
10
15.3
16.5
21.2
22.4
20
10.6
11.8
16.5
18.8
35
9.4
10.6
15.3
16.5
55
8.3
9.4
12.9
16.5
85
7.9
8.2
11.8
15.3
145
7.9
8.2
11.8
14.1
(cm
3
)
17CRF450X31MEY710.indb86 2016/06/0811:46:02
Servicing Your Honda 87
Suspension
6. Pour the recommended fork oil (page 86) into
the outer tube.
Fork Oil Capacity:
Standard oil
capacity
11.0 US oz
(324 cm
3
)
Maximum oil
capacity
13.6 US oz
(402 cm
3
)
Slightly stiffer as
it nears full
compression.
Slightly softer as
it nears full
compression.
Minimum oil
capacity
10.3 US oz
(306 cm
3
)
Standard 26.32 lbf/in (4.61 N/mm) Fork Spring
1 scribe mark
(aftermarket parts)
No mark
(factory products)
or
Optional Softer 25.18 lbf/in (4.41 N/mm) Fork Spring
Standard oil
capacity
11.2 US oz
(330 cm
3
)
Maximum oil
capacity
13.8 US oz
(407 cm
3
)
Slightly stiffer as
it nears full
compression.
Slightly softer as
it nears full
compression.
Minimum oil
capacity
10.5 US oz
(311 cm
3
)
2 scribe mar ks
Optional Stiffer 27.47 lbf/in (4.81 N/mm) Fork Spring
Standard oil
capacity
11.1 US oz
(327 cm
3
)
Maximum oil
capacity
13.7 US oz
(405 cm
3
)
Slightly stiffer as
it nears full
compression.
Slightly softer as
it nears full
compression.
Minimum oil
capacity
10.5 US oz
(309 cm
3
)
3 scribe mar ks
7. Check that the O-ring (9) on the fork
damper (2) is in good condition. Apply
the recommended fork oil to the O-ring.
Temporarily install the fork damper to the
outer tube (1).
After installing the fork leg (page 123),
tighten the fork damper to the specified
torque:
Actual:
25 lbf·ft (34 N·m, 3.5 kgf·m)
Torque wrench scale reading:
23 lbf·ft (31 N·m, 3.2 kgf·m), using a 20 in
(50 cm) long torque wrench.
When using the lock nut wrench, use a 20 in (50
cm) long deflecting beam type torque wrench.
The lock nut wrench increases the torque
wrench’s leverage, so the torque wrench reading
will be less than the torque actually applied to the
fork damper.
(1)
(9)
(2)
(1) outer tube
(2) fork damper
(9) O-r
ing
Be sure the oil capacity is the same in both fork
legs.
17CRF450X31MEY710.indb87 2016/06/0811:46:04
88 Servicing Your Honda
Brakes
Refer to Safety Precautions on page 25.
Both the front and rear brakes are the hydraulic
disc type. As the brake pads wear, the brake fluid
level will drop. A leak in the system will also
cause the level to drop.
Frequently inspect the system to ensure there are
no fluid leaks. Periodically inspect the brake fluid
level and brake pads for wear.
If the front brake lever or rear brake pedal freeplay
does not feel within the normal range while
riding, check the brake pads. If they are not worn
beyond the recommended limit (page 91), there
is probably air in the brake system. Refer to the
Honda Service Manual or see your dealer to have
the air bled from the system.
Rear Brake Pedal Height
The brake pedal height should be approximately
level with the right footpeg.
1. Loosen the lock nut (1) and turn the adjusting
bolt (2) in direction (+) to raise the brake
pedal (3) or in direction (–) to lower it.
2. Tighten the lock nut to the specified torque at
the desired pedal height.
4.4 lbf·ft (5.9 N·m, 0.6 kgf·m)
(2)
(1)
(3)
(+)
(–)
(1) lock nut (+) raise the pedal height
(2) adjusting bolt (–) low
er the pedal height
(3) brake pedal
Front Brake Lever Adjustment
3/8–13/16 in
(10 – 20 mm)
(1)
(2)
(3)
(1) lock nut
(2) adjuster
(3) piston
1. Loosen the lock nut (1).
2. To position the brake lever farther away from
the handgrip, turn the adjuster (2) clockwise.
To position the brake lever closer to the
handgrip, turn the adjuster counterclockwise.
3. While holding the adjuster, tighten the lock
nut to the specified torque:
4.4 lbf·ft (5.9 N·m, 0.6 kgf·m)
4. Apply the brake, release it, then spin the
wheel and check that it rotates freely. Repeat
this procedure several times.
5. Check freeplay by pulling in slowly on the
brake lever until the brake starts to engage.
Freeplay: 3/8 – 13/16 in (10 – 20 mm)
6. Apply silicone grease to the contacting faces
of the adjuster and piston (3).
17CRF450X31MEY710.indb88 2016/06/0811:46:04
Servicing Your Honda 89
Brakes
Fluid Level Inspection
Front Brake Fluid Level Check
(1)
(1) LWR mark
With the motorcycle in an upright position, check
the fluid level.
It should be above the LWR mark (1). If the level
is at or below the LWR mark, check the brake
pads for wear (page 91).
Worn brake pads should be replaced. If the pads
are not worn, have your brake system inspected
for leaks.
If the brake lever freeplay exceeds 13/16 in (20
mm), there is probably air in the brake system
and it must be bled. Refer to the Honda Service
Manual or see your dealer for brake bleeding.
Rear Brake Fluid Level Check
(1)
(1) LOWER mark
With the motorcycle in an upright position, check
the fluid level.
It should be above the LOWER mark (1). If the
level is at or below the LOWER mark, check the
brake pads for wear (page 91).
Worn brake pads should be replaced. If the pads
are not worn, have your brake system inspected
for leaks.
If the brake pedal freeplay exceeds 13/16 in (20
mm), there is probably air in the brake system
and it must be bled. Refer to the Honda Service
Manual or see your dealer for brake bleeding.
17CRF450X31MEY710.indb89 2016/06/0811:46:05
90 Servicing Your Honda
Brakes
Adding Front Brake Fluid
NOTICE
Spilled brake fluid will severely damage
instrument lenses and painted surfaces. It is
also harmful to some rubber parts. Be careful
whenever you remove the reservoir cap: make
sure the reservoir is horizontal first.
• Always use fresh DOT4 brake fluid from a
sealed container when servicing the system.
Do not mix different types of fluid, they may
not be compatible.
• The recommended brake fluid is Pro Honda
DOT4 brake fluid or an equivalent.
(4)
(1)
(2)
(3)
(1) front brake reservoir cap screws
(2) reservoir cap
(3) diaphragm
(4) upper level mark
1. Remove the front brake reservoir cap screws
(1), reservoir cap (2) and diaphragm (3).
2. Fill the reservoir with DOT4 brake fluid to
the upper level mark (4). Do not overfill.
3. Install the diaphragm and reservoir cap.
4. Tighten the front brake reservoir cap screws
to the specified torque:
0.7 lbf·ft (1 N·m, 0.1 kgf·m)
Adding Rear Brake Fluid
NOTICE
Spilled brake fluid will severely damage
instrument lenses and painted surfaces. It is
also harmful to some rubber parts. Be careful
whenever you remove the reservoir cap: make
sure the reservoir is horizontal first.
• Always use fresh DOT4 brake fluid from a
sealed container when servicing the system.
Do not mix different types of fluid, they may
not be compatible.
• The recommended brake fluid is Pro Honda
DOT4 brake fluid or an equivalent.
(5)
(1)
(2)
(3)
(1) rear brake reservoir cap bolts
(2) reserv
oir cap
(3) set plate
(4) diaphragm
(5) upper level mark
1. Remove the rear brake reservoir cap bolts (1),
reservoir cap (2), set plate (3) and diaphragm (4).
2. Fill the reservoir with DOT4 brake fluid to
the upper level mark (5). Do not overfill.
3. Install the diaphragm, set plate and reservoir
cap. Do not bend to the diaphragm during
installation.
4. Install and tighten the
rear brake reservoir cap
bolts to the specified torque:
0.7 lbf·ft (1 N·m, 0.1 kgf·m)
Other Inspection
• Make sure there are no fluid leaks.
• Check for deterioration or cracks in the hoses
and fittings.
(4)
(3)
17CRF450X31MEY710.indb90 2016/06/0811:46:05
Servicing Your Honda 91
Brakes
Brake Pad Wear
Brake pad wear depends on the severity of usage
and track conditions. (Generally, the pads will
wear faster on wet and dirty tracks) Inspect the
pads at each regular maintenance interval (pages
27 and 28).
Front Brake Pads
Inspect the brake pads (1) through the front
wheel to determine the pad wear. If either pad is
worn anywhere to a thickness of 0.04 in (1 mm),
both pads must be replaced.
minimum thickness
indicator
wear indicator
grooves
replace
(2)
(3)
(1)
(1)
0.04 in
(1 mm)
0.04 in
(1 mm)
(1) brake pads
(2) front brake caliper
(3) brake disc
Rear Brake Pads
Inspect the brake pads (1) from the rear side of
the caliper to determine the pad wear. If either
pad is worn anywhere to a thickness of 0.04 in (1
mm), both pads must be replaced.
replace
0.04 in
(1 mm)
minimum thickness
indicator
(3)
(2)
(1)
(1) brake pads
(2) rear brak
e caliper
(3) brake disc
Other Inspections
Check that the brake lever and pedal assemblies
are positioned properly and the securing bolts are
tight.
Make sure there are no fluid leaks. Check for
deterioration or cracks in the hoses and fittings.
17CRF450X31MEY710.indb91 2016/06/0811:46:05
92 Servicing Your Honda
Wheels
Refer to Safety Precautions on page 25.
Keeping the wheels true (round) and maintaining
correct spoke tension is critical to safe
motorcycle operation. During the first few rides,
spokes will loosen more rapidly due to the initial
seating of the parts. Excessively loose spokes
may result in instability at high speeds and the
possible loss of control. It’s also important that
the rim locks are secure to prevent tire slippage.
It is not necessary to remove the wheels to
perform the recommended service in the
Maintenance Schedule (pages 27 and 28).
However, information for wheel removal is
provided for emergency situations.
Wheel Rims & Spokes
(2)
(3)
(1)
(1) wheel rim
(2) spoke
(3) rim loc
k
1. Inspect the wheel rims (1) and spokes (2) for
damage.
2. Tighten, any loose spokes and rim locks (3)
to the specified torque:
Spokes :
(front) 2.7 lbf·ft (3.68 N·m, 0.4 kgf·m)
(rear) 2.7 lbf·ft (3.7 N·m, 0.4 kgf·m)
Rim Locks : 9 lbf·ft (12 N·m, 1.2 kgf·m)
3. Check wheel rim runout. If runout is
noticeable, see the Honda Service Manual for
inspection instructions.
Axles & Wheel Bearings
See the Honda Service Manual for inspection
information:
1. Check the axle shaft for runout.
2. Check the condition of the wheel bearings.
17CRF450X31MEY710.indb92 2016/06/0811:46:05
Servicing Your Honda 93
Tires & Tubes
Refer to Safety Precautions on page 25.
To safely operate your CRF, the tires must be the
proper type (off-road) and size, in good condition
with adequate tread, and correctly inflated.
Using tires that are excessively worn or
improperly in ated can cause a crash in
which you can be seriously hurt or killed.
Follow all instructions in this owner’s
manual regarding tire in ation and
maintenance.
WARNING
The following pages give detailed information on
how and when to check your air pressure, how to
inspect your tires for wear and damage, and our
recommendations on tire replacement.
Air Pressure
Properly inflated tires provide the best
combination of handling, tread life, and riding
comfort. Generally, underinflated tires wear
unevenly, adversely affect handling, and are
more likely to fail from being overheated.
Underinflated tires can also cause wheel damage
on hard terrain. Overinflated tires make your
CRF ride harshly, are more prone to damage
from surface hazards, and wear unevenly.
Make sure the valve stem caps are secure. If
necessary, install new caps.
Always check air pressure when your tires are
“cold.” If you check air pressure when your tires
are “warm” — even if your CRF has only been
ridden for a few miles — the readings will be
higher. If you let air out of warm tires to match
the recommended cold pressures, the tires will be
underinflated.
The correct “cold” tire pressures are:
Front 15 psi (100 kPa, 1.0 kgf/cm
2
)
Rear 15 psi (100 kPa, 1.0 kgf/cm
2
)
If you decide to adjust tire pressures for a
particular riding condition, make changes a little
at a time.
Inspection
Take time to inspect your tires and wheels before
you ride.
• Inspect carefully for bumps or bulges in the
side of the tire or the tread. Replace any tire
that has a bump or bulge.
• Look closely for cuts, slits, or cracks in the
tires. Replace a tire if you can see fabric or
cord.
• Check for rocks or other objects embedded in
the tire or tread. Remove any objects.
• Check the position of both valve stems. A
tilted valve stem indicates the tube is slipping
inside the tire or the tire is slipping on the
rim.
Tube Replacement
If a tube is punctured or damaged, you should
replace it as soon as possible. A repaired tube
may not have the same reliability as a new one,
and it may fail while you are riding.
Use a replacement tube equivalent to the original.
17CRF450X31MEY710.indb93 2016/06/0811:46:05
94 Servicing Your Honda
Tires & Tubes
Tire Replacement
The tires that came on your CRF were designed
to provide a good combination of handling,
braking, durability, and comfort across a broad
range of riding conditions.
Installing improper tires on your
motorcycle can affect handling and
stability. This can cause a crash in which
you can be seriously hurt or killed.
Always use the size and type of tires
recommended in this owner’s manual.
WARNING
Front
80/100-21 51M
DUNLOP D742FA
Rear
110/100-18 64M
DUNLOP D756
Type bias-ply, tube type
• When replacing, use the original equipment
tires or equivalent tires of the same size,
construction, speed rating, and load range as
the originals.
• Replace the tube any time you replace a tire.
The old tube will probably be stretched and, if
installed in a new tire, could fail.
17CRF450X31MEY710.indb94 2016/06/0811:46:05
Servicing Your Honda 95
Side Stand
Refer to Safety Precautions on page 25.
1. Check the side stand spring (1) for damage
and loss of tension.
2. Check the side stand assembly for freedom of
movement.
(1)
(1) side stand spring
If the side stand is stiff or squeaky, clean the
pivot area and lubricate the pivot bolt with
grease.
17CRF450X31MEY710.indb95 2016/06/0811:46:05
96 Servicing Your Honda
Drive Chain
Refer to Safety Precautions on page 25.
An endless (riveted master link) chain connects
the drive and driven sprockets. The O-ring chain
uses rubber between the side plates of the pin and
roller links to seal in the manufacturer-installed
lubricating grease and keep out moisture and dirt.
The service life of the chain depends on proper
lubrication and adjustment. Poor maintenance
can cause premature wear or damage to the drive
chain or sprockets.
Under severe usage, or when the motorcycle is
ridden in unusually dusty or muddy areas, more
frequent maintenance will be necessary.
Before servicing your drive chain, turn the
engine OFF, raise the rear wheel off the ground
by placing an optional workstand or equivalent
support under the engine and check that your
transmission is in neutral.
It is not necessary to remove or replace the drive
chain to perform the recommended service in
the Regular off-road Use Maintenance Schedule
(page 27).
Inspection
1. Stop the engine and raise the rear wheel off
the ground by placing an optional workstand
or equivalent support under the engine and
shift the transmission into neutral.
2. Check the drive chain slack (1) in the upper
drive chain run midway between the drive (2)
and driven sprockets (3). Drive chain slack
should allow the following vertical movement
by hand:
1 – 1 3/8 in (25 – 35 mm)
NOTICE
Excessive chain slack may allow the drive chain
to damage the engine cases.
(1)
(2)
(3)
(1) drive chain slack
(2) drive sprocket
(3) driven sprocket
If the chain is found to be slack in one segment
of its length and taut in another, this indicates
that some of the links are either worn, kinked or
binding. Kinking and binding can frequently be
eliminated by thorough cleaning and lubrication.
If the drive chain requires adjustment, procedure
is as follows:
Adjustment
1. Loosen the rear axle nut (1).
2. Loosen the chain adjuster lock nuts (2) and
turn the adjusting bolts (3) counterclockwise
to decrease slack or clockwise to increase
slack.
Align the index marks (4) of the axle plates
(5) with the same reference marks (6) on both
sides of the swingarm.
(3)
(1)
(2)
(5)(4)
(6)
(1) rear axle nut (4) index mark
(2) chain adjuster lock n
ut (5) axle plate
(3) adjusting bolt (6) reference marks
3. Tighten the rear axle nut to the specified
torque:
94 lbf·ft (128 N·m, 13.1 kgf·m)
4. Recheck chain slack and adjust if necessary.
5. Turn the adjusting bolts counterclockwise until
they touch the axle plates lightly. Then tighten
the chain adjuster lock nuts to the specified
torque while holding the adjusting bolts with a
wrench.
20 lbf·ft (27 N·m, 2.8 kgf·m)
17CRF450X31MEY710.indb96 2016/06/0811:46:05
Servicing Your Honda 97
Drive Chain
Removal, Cleaning & Replacement
For maximum service life, the drive chain should
be cleaned, lubricated, and adjusted before each
outing. Your CRF has an endless (riveted master
link) type chain. It should only be removed or
replaced by your dealer.
The O-rings can be damaged by steam cleaning,
high pressure washers, and certain solvents.
1. Clean the side surfaces of the chain with a
dry cloth. Use a high flash point solvent such
as kerosene – not gasoline.
Do not brush the rubber O-rings. Brushing
will damage them. Use of a solvent may also
damage the O-rings.
2. Replace the drive chain if it has damaged
rollers, loose fitting links, damaged O-rings,
or otherwise appears unserviceable.
3. Measure the drive chain plate (1). If the drive
chain plate is worn anywhere to a thickness
of 0.53 in (13.4 mm), the drive chain must be
replaced.
Replacement chain:
Size/link: DID520MXV/114
0.53 in
(13.4 mm)
(1)
(1) drive chain plate (inner)
4. Inspect the sprocket teeth for possible wear
or damage. Replace them if necessary.
Never install a new drive chain on badly
worn sprockets, or use new sprockets with
a badly worn drive chain. Both chain and
sprockets must be in good condition, or the
new replacement chain or sprocket(s) will
wear rapidly.
Excessively worn sprocket teeth have a
hooked, worn appearance. Replace any
sprocket, which is damaged or excessively
worn.
NOTICE
Use of a new chain with worn sprockets will
cause rapid chain wear.
5. Lubricate the drive chain.
6. Recheck chain slack and adjust if necessary.
17CRF450X31MEY710.indb97 2016/06/0811:46:06
98 Servicing Your Honda
Drive Chain
Drive Chain Sliders
1. Check the chain slider (1) for wear.
If the wear is 0.2 in (5 mm) or more, replace
it.
(1)
0.2 in (5 mm)
(1) chain slider
2. Check the chain guide slider (2) for wear.
Replace the chain guide slider if it is worn to
the bottom of the wear limit (3).
(3)
(2)
(2) chain guide slider
(3) wear limit
Lubrication
Lubricate the drive chain with Pro Honda HP
Chain Lube or an equivalent chain lubricant
designed specifically for use on O-ring chains.
Wipe off the excess chain lubricant.
Commercial chain lubricants not designed for
motorcycle drive chains may contain solvents
which could damage the O-rings.
Drive Chain Rollers
1. Measure the diameter of the upper (1) and
lower drive chain rollers (2). Replace them if
below the service limit.
Service Limit:
UPPER ROLLER: 1.5 in (39 mm)
LOWER ROLLER: 1.4 in (35 mm)
2. Replace the roller if necessary as follows:
Install the upper drive chain roller (Green)
with the “
” mark (3) facing toward the
frame and lower drive chain roller (Black)
with the “
” mark (3) side facing out.
Tighten the drive chain roller bolt and nut to
the specified torque:
Upper roller bolt:
9 lbf·ft (12 N·m, 1.2 kgf·m)
Lower roller nut:
9 lbf·ft (12 N·m, 1.2 kgf·m)
(3)
(3)
(1)
(2)
(1) upper drive chain roller (Green)
(2) lower dr
ive chain roller (Black)
(3) “
” mark
17CRF450X31MEY710.indb98 2016/06/0811:46:06
Servicing Your Honda 99
1. Remove the front visor bolts (1) and pull out
the front visor (2).
(2)
(1)
(1) front visor bolts
(2) front visor
2. Disconnect the headlight connector (3).
(3)
(3) headlight connector
Steering Damper
(cont’d)
Refer to Safety Precaution on page 25.
Loose, worn or damaged steering damper
components may adversely affect the handling
and stability of your CRF. If any steering
damper components appear worn or damaged,
see your dealer for further inspection. Your
dealer is qualified to determine whether or not
replacement parts are needed.
Do not attempt to disassemble the steering
damper; see your dealer.
The instructions found in this owner’s manual are
limited to adjustment and service of the steering
damper assembly only.
Steering Damper Operation Inspection
• When your CRF is new, break it in for
approximately 1 hour to ensure that the
steering damper has worked in (page 21).
• After break-in, test run your CRF with the
steering damper at the standard setting before
making any adjustments.
• Check the spherical bearings and dust seal for
dust, dirt, and foreign materials.
• Make all damping adjustments in one-click
increments. (Adjusting two or more clicks at
a time may cause you to pass over the best
adjustment.) Test ride after each adjustment.
• If you have a problem finding an acceptable
adjustment, return to the standard position and
begin again.
3. Check the steering damper (4) for
deformation or oil leaks.
Check the damper
rod (5) for bending or damage.
Replace the
damper case or damper rod if there is any
abnormality.
Refer to Honda Service Manual
or see your dealer for steering damper
disassembly.
Check the torque of the steering
damper mounting bolts (6):
15 lbf·ft (20 N·m, 2.0 kgf·m)
(5)
(4)
(6)
(4) steering damper
(5) damper rod
(6) steering damper mounting bolts
4. With your CRF on a box or an optional
workstand (front wheel elevated), check that
the steering moves smoothly from side-to-
side.
17CRF450X31MEY710.indb99 2016/06/0811:46:07
100 Servicing Your Honda
Inspection
1. Check the damper rod (1) operation.
The damper rod is fully extended and
compressed by hand. Release the damper rod,
then check that it extends to its maximum
length.
If the damper rod does not extend to its
maximum length, disassemble and inspection
for steering damper.
Refer to the Honda Service Manual or see
your dealer.
(1)
(1) damper rod
Removal
1. Remove the front visor (page 99).
2. Remove the steering damper mounting bolts
(1), collar A (2), collar B (3) and steering
damper (4).
(4)
(1)
(2)
(3)
(1) steering damper mounting bolts
(2) collar A
(3) collar B
(4) steering damper
5. Connect the headlight connector (3). Install
the front visor (2) by aligning its grommets
(7) with the tabs (8) on the steering stem.
Install and tighten the front visor bolts (1).
(8)
(7)
(2)
(3)
(2) front visor (7) grommets
(3) headlight connector (8) tabs
(1)
(1) front visor bolts
Steering Damper
17CRF450X31MEY710.indb100 2016/06/0811:46:07
Servicing Your Honda 101
5. With your CRF on a box or an optional
workstand (front wheel elevated), check that
the steering moves smoothly from side-to-
side.
6. Install the front visor (page 100).
Installation
1. Clean and apply a locking agent to the
steering damper mounting bolt threads.
2. Install the steering damper (1) with its “UP”
mark (2) facing up and forward. Turn the
damper rod and its stopper ring (3) facing
toward the front side.
3. Install the collar A (4), collar B (5) and
steering damper mounting bolts (6).
Be sure to install the collar A and collar B
with its wide flange side facing toward the
steering head pipe side.
4. Tighten the steering damper mounting bolts
to the specified torque:
15 lbf·ft (20 N·m, 2.0 kgf·m)
(4)
(1)
(2)
(5)
(6)
(3)
(1) steering damper
(2) “UP” mar
k
(3) stopper ring
(4) collar A
(5) collar B
(6) steering damper mounting bolts
2. Check the condition of the spherical bearings
(2). Move the spherical bearing with your
finger. The spherical bearing should move
smoothly and quietly.
Replace the spherical bearing if it does not
move smoothly and quietly.
Refer to the Honda Service Manual or see
your dealer.
(2)
(2) spherical bearings
Steering Damper
17CRF450X31MEY710.indb101 2016/06/0811:46:07
102 Servicing Your Honda
Additional Maintenance Procedures
Refer to Safety Precautions on page 25.
Steering Head Bearing Inspection
1. With your CRF on a box or optional
workstand (front wheel elevated), turn the
handlebar to the right and left to check for
roughness in the steering head bearings.
2. Stand in front of your CRF, grab the fork (at
the axle), look at the steering head, and push
the fork in and out (toward the engine) to
check for play in the steering head bearings.
Handlebar Inspection
1. Remove the handlebar pad.
2. Check the handlebar (1) for bends or cracks.
3. Check that the handlebar has not moved from
its proper position (by inspecting the paint
mark (2)).
4. Check the torque of the handlebar upper
holder bolts (3):
16 lbf·ft (22 N·m, 2.2 kgf·m)
Tighten the front bolts first.
(2)
(1)
(3)
(1) handlebar
(2) paint mark
(3) handlebar upper holder bolts
Control Cables
Periodically, disconnect the throttle, clutch
and hot start cables at their upper ends.
Thoroughly lubricate the cable pivot points with
a commercially available cable lubricant. If the
clutch lever, hot start lever and throttle operation
is not smooth, replace the cable.
Be sure the throttle returns freely from fully
open to fully closed automatically, in all steering
positions.
If any roughness or play is felt, but you do
not see any movement in the steering head,
the fork bushings may be worn. Refer to the
Honda Service Manual for replacement or
adjustment procedures, or see your dealer.
17CRF450X31MEY710.indb102 2016/06/0811:46:07
Servicing Your Honda 103
Additional Maintenance Procedures
Nuts, Bolts, Fasteners
Check and tighten nuts, bolts, and fasteners
before every outing.
Item
1
2
3
4
5
6
7
8
9
10
11
12
13
Cylinder head cover bolts
Clutch cover bolts
Water pump cover bolts
Transmission oil check
bolt
Crankshaft hole cap
Oil filter cover bolts
Cylinder bolt
Cylinder head bolts
Exhaust pipe joint nuts
Drive sprocket bolt
Engine oil drain bolt
Transmission oil drain
bolt
Coolant drain bolt
ENGINE
Torque
lbf
•
ft N
•
m kgf
•
m
7
7
7
7
11
7
7
7
15
23
12
12
7
10
10
10
10
15
10
10
10
21
31
16
16
10
1.0
1.0
1.0
1.0
1.5
1.0
1.0
1.0
2.1
3.2
1.6
1.6
1.0
(1) cylinder head cover bolts
(2) clutch cover bolts
(3) water pump cover bolts
(4) transmission oil check bolt
(5) crankshaft hole cap
(9) exhaust pipe joint nuts
(13) coolant drain bolt
(1)
(9)
(5)
(4)
(2)
(3)
(13)
(8)
(10)
(7)
(12)
(11)
(6)
RIGHT SIDE
LEFT SIDE
(6) oil lter co
ver bolts
(7) cylinder bolt
(8) cylinder head bolts
(10) drive sprocket bolt
(11) engine oil drain bolt
(12) transmission oil drain bolt
17CRF450X31MEY710.indb103 2016/06/0811:46:08
104 Servicing Your Honda
Battery
Refer to Safety Precautions on page 25.
Your CRF has a maintenance-free type battery.
You do not have to check the battery electrolyte
level or add distilled water as you would with a
conventional-type battery.
NOTICE
Your battery is a maintenance-free type and
can be permanently damaged if the cap strip is
removed.
Electrical accessories use current from the
battery, even when the engine is stopping.
Limited operation also allows the battery to
discharge. If you have electrical accessories
on your CRF or do not ride frequently, we
recommended that you charge the battery
frequently (see Battery Charging on page 105).
If you do not expect to ride your CRF for at
least 2 weeks, we recommended you remove the
battery, or at least disconnect the battery cables
(negative cable first).
If you plan to store your CRF, see Battery
Storage (this page).
If your battery seems weak and/or is leaking
electrolyte (cause slow starting or other electrical
problems), see your dealer.
WARNING: Battery posts, terminals and related
accessories contain lead and lead compounds.
Wash hands after handling.
Battery Storage
If you plan to store your CRF, we recommend
you remove the battery and store it where it can
be charged at least every 30 days to maintain its
service life.
If you do not remove the battery, we recommend
disconnecting the battery cables (negative cable
first).
You will get the best storage results from removing
the battery and slow charging it every 30 days (see
Battery Charging on page 105).
Before you remove the battery, be sure to read
all the information that follows, as well as the
information on the battery label.
The battery gives off explosive hydrogen
gas during normal operation.
A spark or ame can cause the battery
to explode with enough force to kill or
seriously hurt you.
Wear protective clothing and a face
shield, or have a skilled mechanic do the
battery maintenance.
WARNING
The battery is located under the seat.
Removal
1. Remove the seat (page 36).
2. Remove the battery band (1).
3. Remove the positive terminal cover (2).
4. Disconnect the negative (–) terminal (3) first,
then the positive (+) terminal (4) and remove
the battery (5).
(1)
(5)
(2)
(3)
(4)
(1) battery band (4) positive (+) terminal
(2) positive t
erminal cover (5) battery
(3) negative (–) terminal
5. Unless you have been riding regularly, charge
the battery (see page 105).
6. Store your battery in an easy-to-reach
location off the floor, in an area protected
from freezing temperatures and direct
sunlight.
7. Clean the battery box after removing the
battery for storage. Dry the battery box.
8. Slow charge the battery (see page 105) once
every 30 days.
Installation
1. Reinstall the battery in the reverse order of
removal. Be sure to connect the positive (+)
terminal first, then the negative (–) terminal.
2. Check all the bolts and other fasteners are
secure.
3. Install the battery band (1) as shown.
(1)
(1) battery band
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Servicing Your Honda 105
Battery
Battery Charging
Be sure to read the information that came with
your battery charger and follow the instructions
on the battery. Improper charging may damage
the battery.
We recommended using a charger (1) designed
specifically for your Honda, which can be
purchased from your dealer. These units can
be left connected for long periods without
risking damage to the battery. However, do
not intentionally leave the charger connected
longer than the time period recommended in the
charger’s instructions.
Avoid using an automotive-type battery charger.
An automotive charger can overheat a motorcycle
battery and cause permanent damage.
(1)
(1) charger
17CRF450X31MEY710.indb105 2016/06/0811:46:08
106 Servicing Your Honda
Headlight & Taillight
Refer to Safety Precaution on page 25.
Headlight Bulb
1. Remove the front visor bolts (1) and pull out
the front visor (2).
(2)
(1)
(1) front visor bolts
(2) front visor
2. Disconnect the headlight connector (3).
Remove the dust cover (4).
(3)
(4)
(3) headlight connector
(4) dust cover
3.
To pull the headlight bulb out, push
and turn the headlight bulb socket (5)
counterclockwise.
(5)
(5) headlight bulb socket
4. Install a new headlight bulb (6) into the
headlight unit while aligning the tab (7) with
the groove (8) of the headlight unit.
If you touch the bulb with your bare hands, clean
it with a cloth moistened with denatured alcohol
to prevent early bulb failure.
(6)
(7)
(8)
(6) headlight bulb
(7) tab
(8) gr
oove
5. To install the headlight bulb socket (5), push
and turn it clockwise.
6. Install the dust cover (4) tightly against the
headlight unit with its “TOP” mark (9) facing
up.
(4)
(9)
(5)
(4) dust cover
(5) headlight bulb socket
(9) “TOP” mark
7. Connect the headlight connector (3).
Install the front visor by aligning its
grommets (10) with the tabs (11) on the
steering stem.
Install and tighten the front visor bolts.
(3)
(10)
(11)
(3) headlight connector
(10) gr
ommets
(11) tabs
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Servicing Your Honda 107
Headlight & Taillight
Headlight Aim
The headlight aim can be raised or lowered.
Turn the adjusting screw (1) clockwise to move
the headlight up or turn the adjusting screw
counterclockwise to move the headlight down to
proper adjustment.
(1)
(1) adjusting screw
Taillight
The taillight uses LED illumination.
If the taillight does not function properly, see
your dealer for service.
This model is equipped with an electric starter
and battery for easy engine starting.
There is a possibility of damage to the lighting
system if the battery is carelessly removed.
Never kick-start the engine without the battery
connected.
If it becomes necessary to kick-start the engine
with the battery removed, remove the relays to
the battery to prevent damage to the lighting.
17CRF450X31MEY710.indb107 2016/06/0811:46:09
108 Servicing Your Honda
Appearance Care
Refer to Safety Precautions on page 25.
Frequent cleaning and polishing will keep your
Honda looking newer longer. Frequent cleaning
also identifies you as an owner who values his
motorcycle. A clean CRF is also easier to inspect
and service.
While you’re cleaning, be sure to look for
damage, wear, and gasoline or oil leaks.
General Recommendations
• To clean your CRF you may use:
– water
– a mild, neutral detergent and water
– a mild spray and wipe cleaner/polisher
– a mild spray and rinse cleaner/degreaser and
water
• Avoid products that contain harsh detergents
or chemical solvents that could damage the
metal, paint, and plastic on your CRF or
discolor the seat and decals.
• If your CRF is still warm from recent
operation, give the engine and exhaust system
time to cool off.
• We recommend the use of a low pressure
garden hose to wash your CRF. High pressure
washers (like those at coin-operated car
washes) can damage certain parts of your
CRF. The force of water under extreme
pressure can penetrate the dust seals of the
suspension pivot points and steering head
bearings-driving dirt inside and needed
lubrication out.
If you use a high pressure washer, avoid spraying
the following areas:
wheel hubs
muffler outlet
area under seat
engine stop button
brake master cylinders
under fuel tank
drive chain
carburetor
steering head bearings
suspension pivot points
(2)
(1)
(1) steering head bearings
(2) suspension pivot points
NOTICE
High pressure water (or air) can damage certain
parts of your CRF.
You may use Pro Honda Hondabrite, a multi-
surface cleaner/degreaser, to remove both dirt and
petroleum-based grime from paint, alloy, plastic,
and rubber surfaces. Wet any heavy deposits
with water first. Then spray on the Pro Honda
Hondabrite and rinse with a garden hose at full
pressure. Stubborn deposits may require a quick
wipe with a sponge.
Washing Your Motorcycle with a Mild
Detergent
1. Rinse your CRF thoroughly with cool water
to remove loose dirt.
2. Fill a bucket with cool water. Mix in a mild,
neutral detergent, such as dish washing liquid
or a product made especially for washing
motorcycles or automobiles.
3. Wash your CRF with a sponge or a soft
towel. As you wash, check for heavy grime.
If necessary, use a mild cleaner/degreaser to
remove the grime.
NOTICE
Do not use steel wool to clean the frame as it
could damage or discolor the frame surface.
Muffler stain remover (Scotch Brite Hand Pad
#7447-maroon) is for removing stains on the non-
coated aluminum frame only.
4. After washing, rinse your CRF thoroughly
with plenty of clean water to remove any
residue.
Detergent residue can corrode alloy parts.
5. Dry your CRF with a chamois or a soft towel.
Leaving water on the surface to air dry can
cause dulling and water spots.
As you dry, inspect for chips and scratches.
6. Lubricate the drive chain to prevent rusting.
7. Start the engine and let it idle for several
minutes. The engine heat will help dry moist
areas.
8. As a precaution, ride at a slow speed and
apply the brakes several times. This will help
dry the brakes and restore normal braking
performance.
If the inside of the headlight lens appears clouded
immediately after washing, it should clear after a
few minutes of riding.
17CRF450X31MEY710.indb108 2016/06/0811:46:09
Servicing Your Honda 109
Appearance Care
After Cleaning Lubrication
There are some things you should do just after
washing your CRF to help prevent rust and
corrosion.
Once your CRF is clean and dry, you should
protect any bare steel from rusting by applying
a light coating of a rust-inhibitor. Lubricate the
drive chain and drive sprocket after removing and
thoroughly cleaning in solvent. Be sure the chain
is wiped clean and is dry before applying the
chain lube.
Follow the suggestions given in the pages of this
manual for lubricating items such as the brake and
clutch lever pivot points and footpeg pivot pins.
Aluminum Frame Maintenance
Aluminum corrodes when it comes in contact
with dust, mud and road salt.
To remove stains, use Scotch-Brite Hand Pad
#7447 (maroon) or an equivalent.
Wet the pad and polish the surface using strokes
parallel to the length of the frame.
Clean the frame using a wet sponge and a mild
detergent, then rinse well with clean water. Dry
the frame with a soft clean cloth, using strokes
parallel to the length of the frame.
NOTICE
Do not use steel wool to clean the frame as it
could damage or discolor the frame surface.
Muffler stain remover (Scotch-Brite Hand Pad
#7447-maroon) is for removing stains on the non-
coated aluminum frame only.
Exhaust Pipe And Muffler Maintenance
The exhaust pipe and muffler are stainless steel
but may become stained by mud or dust.
To remove mud or dust, use a wet sponge and a
liquid kitchen abrasive, then rinse well with clean
water. Dry with chamois or a soft towel.
If necessary, remove heat stains by using a
commercially available fine texture compound.
Then rinse by the same manner as removing mud
or dust.
When the exhaust pipe and muffler are painted,
do not use a commercially available abrasive
kitchen cleaning compound. Use a neutral
detergent to clean the painted surface on the
exhaust pipe and muffler.
If you are not sure if your exhaust pipe and
muffler are painted, contact your dealer.
Condensation Control
Some condensation can form within the
transmission cavity as well. This is natural and
just one more reason you should change the
engine and transmission oil often.
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110 Servicing Your Honda
17CRF450X31MEY710.indb110 2016/06/0811:46:09
Blank page
Adjustments for Competition 111
Adjustments for Competition
This section tells you how to fine tune your CRF
for maximum competition performance.
Initial suspension adjustments should be
performed after a minimum of 2 hours of easy
break-in time.
Optional front and rear suspension springs are
available in both stiffer and softer than standard
rates, in order to tailor your CRF specifically for
your weight, riding style and course conditions.
Follow the instructions given in the rear
suspension sag setting section of Rear Suspension
Adjustments to determine if your combined rider
and sprung machine weight (rider fully dressed
for competition and machine coolant, oil and fuel
levels ready for competition) requires an optional
stiffer or softer rear spring. The need for either
optional rear spring may need to be balanced by
installing the optional fork springs of a similar
rate.
Front Suspension Adjustments ........................112
Front Suspension Air Pressure ................... 112
Front Suspension Damping ........................112
Fork Springs ...............................................113
Front Suspension Disassembly ...................113
Damper Oil Change ....................................117
Fork Assembly ............................................ 120
Rear Suspension Adjustments ..........................126
Rear Suspension Spring Pre-Load .............126
Rear Suspension Damping .........................127
Rear Suspension Race Sag .........................128
Suspension Adjustments for Track
Conditions ........................................................ 130
Suspension Adjustment Guidelines .................131
Carburetor Adjustments & Tuning Tips ........... 134
Carburetor Components..............................134
Carburetor Removal ...................................136
Carburetor Disassembly .............................137
Carburetor Assembly ..................................139
Idle Speed Adjustment ............................... 140
Steering Damper Adjustment ........................... 141
Steering Damper Adjustment ....................141
Steering Damper Adjustment Guidelines ........142
Chassis Adjustments ........................................143
Rear End .....................................................143
Fork Height/Angle ......................................143
Wheelbase...................................................143
Gearing .............................................................144
Tire Selection for Track Conditions ................145
Personal Fit Adjustments .................................146
Control Positioning.....................................146
Handlebar Position, Width & Shape ..........146
17CRF450X31MEY710.indb111 2016/06/0811:46:09
112 Adjustments for Competition
Front Suspension Adjustments
The front suspension can be adjusted for the
rider’s weight and riding conditions by using one
or more of the following methods:
• Oil volume — The effects of higher or lower
fork oil capacity are only felt during the final
3.9 in (100 mm) of fork travel.
• Compression damping — Turning the
compression damping adjuster adjusts how
quickly the fork compresses.
• Rebound damping — Turning the rebound
damping adjuster adjusts how quickly the fork
extends.
• Fork springs — Optional springs are
available in softer and stiffer types than the
standard rate. (page 169)
The inverted fork on your CRF features sealed
damper cartridges with dual (separate air and oil)
chambers to prevent aeration. The design also
isolates the oil in each fork tube/slider, which
may contain air bubbles and/or metal particles,
from the sealed cartridge to provide more
consistent damping.
(1)
(2)
(1) compression damping adjuster
(2) rebound damping adjuster
Front Suspension Air Pressure
Air is an unstable gas which builds up pressure
as it is worked (such as in a fork). Air pressure
acts as a progressive spring and affects the entire
range of fork travel. This means the fork action
on your CRF will get stiffer during a race. For
this reason, release built-up air pressure in the
fork legs between motos. Be sure the fork is fully
extended with the front tire off the ground when
you release the pressure.
The standard air pressure is 0 psi (0 kPa, 0 kgf/
cm
2
). You may relieve accumulated air pressure
in the fork legs by using the fork air pressure
release screws. The front wheel should be off
the ground before you release the pressure. The
air pressure should be adjusted according to the
altitude and outside temperature.
1. Place an optional workstand under the
engine, so that the front wheel is off the
ground. Do not adjust air pressure with the
front wheel on the ground as this will give
false pressure readings.
2. Remove the fork air pressure release screw (1).
3. Check that the O-ring (2) is in good
condition.
4. Install and tighten the fork air pressure
release screw to the specified torque:
0.9 lbf·ft (1.2 N·m, 0.1 kgf·m)
(1)
(2)
(1) fork air pressure release screw (2) O-ring
Front Suspension Damping
Rebound Damping Adjustment
The fork rebound damping adjuster (1) has 16
positions or more. Turning the adjuster screw one
full turn clockwise advances the adjuster four
positions. To adjust the rebound damping to the
standard setting, proceed as follows:
Turn the adjuster clockwise until it will no longer
turn (lightly seats). This is the full hard position.
The adjuster is set in the standard position when
the adjuster is turned counterclockwise 6 clicks.
Make sure that both fork legs are adjusted to the
same position.
Compression Damping Adjustment
This adjustment affects how quickly the fork
compresses. The fork compression damping
adjuster (2) has 16 positions or more. Turning
the adjuster screw one full turn changes the
adjuster four positions. To adjust the compression
damping adjuster to the standard position,
proceed as follows:
Turn the adjuster clockwise until it will no longer
turn (lightly seats). This is the full hard position.
The adjuster is set in the standard position when
the adjuster is turned counterclockwise 11 clicks.
Make sure that both fork legs are adjusted to the
same position.
17CRF450X31MEY710.indb112 2016/06/0811:46:10
Adjustments for Competition 113
Front Suspension Adjustments
Both compression and rebound damping can be
increased by turning the adjuster clockwise.
NOTICE
Always start with full hard when adjusting
damping.
Do not turn the adjuster screw more than the
given positions or the adjuster may be damaged.
Be sure that the rebound and compression
adjusters are firmly located in a detent, and not
between positions.
(1)
(2)
(1) rebound damping adjuster
(2) compression damping adjuster
Front Suspension Disassembly
• If your CRF is brand-new, put enough part-
throttle break-in time (about 1 hour) on it to
ensure that the suspension has worked in.
• For optimum performance, and extended
fork life, the fork should be completely
disassembled and cleaned after the first 3
hours of riding. See the Service Manual or
your dealer for this service.
• When disassembling the fork, turn the
rebound (1) and compression (2) damping
adjusters counterclockwise to the softest
position to prevent damaging the adjustment
needle (be sure to record the number of turns
from the starting position).
(1)
(2)
(1) rebound damping adjuster
(2) compression damping adjuster
Fork Springs
The fork springs in CRF’s are about right for
riders weighing between 150 lb (68 kg) and
160 lb (73 kg) (less riding gear). So if you're
a heavier rider, you have to go up on the oil
capacity or get a stiffer spring. Do not use less
oil than the minimum specified for each spring
or there will be a loss of rebound damping
control near full extension. If the fork is too
hard on big bumps, turn the damping adjuster
counterclockwise 1-turn and lower the oil
capacity in increments of 0.2 oz (5 cm
3
) in
both fork legs until the desired performance is
obtained. Do not, however, lower the oil capacity
below the minimum oil capacity.
Minimum oil level:
Standard spring: 10.3 US oz (306 cm
3
)
Softer spring: 10.5 US oz (311 cm
3
)
Stiffer spring: 10.5 US oz (309 cm
3
)
When adjusting oil capacity, bear in mind that
the air in the fork will increase in pressure while
riding; therefore, the higher the oil capacity, the
higher the eventual pressure of any air in the
fork.
Force (N)
Stroke (mm)
Oil level 13.6 US oz (402 cm
3
)
(MAX)
O
il level 11.0 US oz (324 cm
3
)
(STA
NDARD)
Oil level 10.3 US oz (306 cm
3
)
(MI
N)
17CRF450X31MEY710.indb113 2016/06/0811:46:10
114 Adjustments for Competition
Front Suspension Adjustments
3. Loosen the fork bridge upper pinch bolts (5).
4. Loosen the fork damper (6) using a lock nut
wrench (7), but do not remove it yet.
NOTICE
Do not use an adjustable wrench to loosen the
fork damper: it may damage them.
(5)
(6)
(7)
(5) fork bridge upper pinch bolts
(6) fork damper
(7) loc
k nut wrench
5. Remove the disc cover (8) by removing the
disc cover bolts (9).
(8)
(9)
(8) disc cover
(9) disc cover bolts
6. Remove the tripmeter cable (10) and front
axle nut (11) and loosen the axle pinch bolts
(12) on both fork legs.
7. Pull the front axle shaft (13) out of the wheel
hub and remove the front wheel.
(12)
(10)
(13)
(11)
(12)
(10) tripmeter cable (12) axle pinch bolts
(11) front axle n
ut (13) front axle shaft
8. Remove the fork protector bolts (14),
tripmeter cable clamp screws (15), brake hose
clamp bolts (16) and fork protectors (17).
Remove the brake caliper mounting bolts (18)
and brake caliper (19).
The fork protector bolts and caliper mounting
bolts have a locking agent applied.
1. Place your CRF on an optional workstand or
equivalent support with the front wheel off
the ground.
2. Remove the steering damper (page 100) and
handlebar pad. Remove the handlebar lower
holder nuts, washers, mounting rubbers (3)
and handlebar (4).
NOTICE
Keep the master cylinder upright to prevent air
from entering system.
(4)
(3)
(3) handlebar lower holder nuts/washers/mounting
rubbers
(4) handlebar
17CRF450X31MEY710.indb114 2016/06/0811:46:11
Adjustments for Competition 115
Front Suspension Adjustments
10. Clean the fork assembly, especially the
sliding surface (21) of the slider and fork dust
seal (22).
11. Measure the length (23) between the axle
holder and outer tube and record it before
disassembling the fork.
(23)
(22)
(21)
(21) sliding surface
(22) fork dust seal
(23) length
12. Hold the outer tube (24), then remove the fork
damper (6) from the outer tube using a lock
nut wrench (7). Gently slide the outer tube
down onto the lower end (axle holder) (25).
(7)
(24)
(6)
(24)
(25)
(6) fork damper (24) outer tube
(7) lock nut wr
ench (25) axle holder
NOTICE
The outer tube (24) can drop on the slider (26)
and damage the fork dust seal (22) and guide
bushing (27) when the fork damper is removed.
To avoid damage hold both the outer tube and
slider when removing the fork damper.
(27)
(22)
(24)
(26)
(22) fork dust seal (26) slider
(24) outer tube
(27) guide bushing
13. Drain the fork oil from the outer tube/slider
(28).
Drain the fork oil from the oil holes (29) of
the fork damper.
(28)
(29)
(28) outer tube/slider
(29) oil holes
Do not support the brake caliper by the brake
hose. Do not operate the brake lever after the
front wheel is removed. To do so will cause
difficulty in fitting the brake disc between the
brake pads.
(19)
(16)
(15)
(17)
(18)
(14)
(14)
(14) fork protector bolts
(15) tripmet
er cable clamp screws
(16) brake hose clamp bolts
(17) fork protectors
(18) brake caliper mounting bolts
(19) brake caliper
9. Loosen the fork bridge lower pinch bolts
(20), then pull the fork legs down and out.
(20)
(20) fork bridge lower pinch bolts
(cont’d)
17CRF450X31MEY710.indb115 2016/06/0811:46:11
116 Adjustments for Competition
Front Suspension Adjustments
20. Remove the push rod (33) from the fork damper.
21. Remove the piston base (31) or mechanic's
stopper tool between the axle holder (25) and
fork center bolt lock nut (32) while pushing
the fork damper.
NOTICE
Be careful not to damage the lock nut and fork
center bolt hole.
(25)
(31)
(33)
(32)
(25) axle holder (32) fork center bolt lock nut
(31) piston base (33) push r
od
22. Remove the fork damper assembly (34) from
the fork assembly (35). Remove the fork
from the vise. Remove the fork spring (36)
from the fork assembly.
(35)
(34)
(36)
(34) fork damper assembly (36) fork spring
(35) fork assemb
ly
17. Make the mechanic's stopper tool out of a
thin piece of steel (0.08 in (2.0 mm) thick) as
shown if you do not have the special tool.
18.
2.2 in (55 mm)
1.0 in (25 mm)
R0.30 in
(7.5
mm)
0.6 in (15 mm)
1.5 in (39 mm)
Push out the fork center bolt (30) from the
axle holder (25) of the slider by pushing the
fork damper. While the fork center bolt is
pushed out, install the piston base (31) or
a mechanic’s stopper tool between the axle
holder and fork center bolt lock nut (32).
19. Hold the fork center bolt lock nut and remove
the fork center bolt from the fork damper.
NOTICE
Do not remove the lock nut from the fork damper
piston rod. If the lock nut is removed, the piston
rod will fall in the fork damper and you cannot
reassemble the fork damper.
(25)
(31)
(32)
(30)
(25) axle holder (31) piston base
(30) fork center bolt (32) fork center bolt lock nut
14. Temporarily install the fork damper to the
outer tube.
15. Place the lower end (axle holder) (25) of the
slider in a vise with a piece of wood or soft
jaws to avoid damage.
NOTICE
Over-tightening the vise can damage the axle
holder.
16. Loosen the fork center bolt (30).
(30)
(25)
(25) axle holder
(30) fork center bolt
17CRF450X31MEY710.indb116 2016/06/0811:46:12
Adjustments for Competition 117
Front Suspension Adjustments
6. Extend the fork damper piston rod to
maximum. Pour the recommended fork oil
into the fork damper (1).
Recommended Oil:
Pro Honda HP Fork Oil 5 W or equivalent
Recommended Amount:
6.5 US oz (192 cm
3
, 6.8 Imp oz)
(1)
(1) fork damper
7. Pump the fork damper piston rod (6) slowly
several times to bleed the air from the fork
damper (1).
(1)
(6)
(1) fork damper
(6) fork damper pist
on rod
3. Remove the fork cap assembly (2) from the
fork damper (1).
Be careful not to damage the fork cap bushing.
Do not disassemble the fork cap assembly.
Replace the fork cap as an assembly if it is
damaged.
(1)
(2)
(1) fork damper
(2) fork cap assemb
ly
4. Empty the fork oil from the oil holes (4)
of the fork damper spring chamber (5) by
pumping the damper rod several times.
(5)
(4)
(4) oil holes
(5) fork damper spr
ing chamber
5. Clean the fork cap and fork damper threads.
Damper Oil Change
1. Place the fork damper (1) in a vise with a
piece of wood or soft jaws to avoid damage.
2. Loosen the fork cap assembly (2) while
holding the fork damper using a lock nut
wrench (3).
(1)
(3)
(2)
(1) fork damper
(2) fork cap assembly
(3) lock nut wrench
(cont’d)
17CRF450X31MEY710.indb117 2016/06/0811:46:13
118 Adjustments for Competition
Front Suspension Adjustments
13. Screw in the fork center bolt lock nut (9) to
the fork damper piston rod (6) fully.
(6)
(9)
(6) fork damper piston rod
(9) fork cent
er bolt lock nut
Turn the rebound adjuster and compression
adjuster counterclockwise to the softest position.
Check the fork damper piston rod sliding surface
for damage.
Apply fork oil to the fork damper piston rod
sliding surface.
Cover the fork damper piston rod end with soft
jaws (10) to prevent fork damage.
NOTICE
Be careful not to bend or damage the fork
damper piston rod when the piston rod is stroked.
10. Place the fork damper (1) in a vise with a
piece of wood or soft jaws to avoid damage.
11. Tighten the fork cap assembly (2) while
holding the cut out of the fork damper using
a lock nut wrench (3) to the specified torque:
22 Ibf·ft (30 N·m, 3.1 kgf·m)
(1)
(3)
(2)
(1) fork damper
(2) fork cap assembly
(3) lock nut wrench
12. Hold the fork damper (1) in an upright
position and pump the fork damper piston rod
(6) to 3.9 in (100 mm) slowly several times.
(1)
(6)
(1) fork damper
(6) fork damper pist
on rod
8. Extend the fork damper piston rod to
maximum. Adjust the oil level of the fork
damper (1) as shown.
Oil Level: 1.7 – 1.9 in (42 – 47 mm)
1.7 – 1.9 in
(42 – 47 mm)
(1)
(1) fork damper
9. Apply fork oil to the bushing (7) and new
O-rings (8) on the fork cap assembly (2).
Extend the fork damper piston rod to
maximum, holding it, install the fork cap
assembly to the fork damper (1).
Be careful not to damage the fork cap bushing.
If it is difficult to install the fork cap assembly,
the fork damper oil level might be higher than
standard oil level. Inspect the fork damper oil
level again.
(1)
(2)
(7)
(8)
(1) fork damper (7) bushing
(2) fork cap assembly (8) O-rings
17CRF450X31MEY710.indb118 2016/06/0811:46:13
Adjustments for Competition 119
Front Suspension Adjustments
15. Drain the extra oil from the oil holes (4) of
the fork damper spring chamber (5).
By doing this procedure, about 0.6 US oz (17
cm
3
) of fork fluid will be drained from the
damper spring chamber through the oil hole and
cause 5.9 US oz (175 cm
3
) of fork fluid to be left
in the chamber.
(5)
(4)
(4) oil holes
(5) fork damper spr
ing chamber
14. Blow the extra oil off to the fork damper
spring chamber (5) by pumping the fork
damper piston rod to full stroke.
(5)
(10)
(5) fork damper spring chamber
(10) soft ja
w s
16. Blow out the oil from the fork damper spring
chamber using compressed air to the oil hole.
Wipe the oil completely off the fork damper.
17. If you can not use compressed air, remove
the fork air pressure release screw (11) on the
fork cap (12).
Hold the fork damper upside down for 10
minutes and drain the oil from the fork
damper spring chamber.
(12)
(11)
(11) fork air pressure release screw
(12) for
k cap
Pour the drained oil into a suitable container and
dispose of it in an approved manner (page 151).
NOTICE
Improper disposal of drained fluids is harmful to
the environment.
17CRF450X31MEY710.indb119 2016/06/0811:46:14
120 Adjustments for Competition
Front Suspension Adjustments
Fork Assembly
1. Drain the fork oil from the fork assembly (1)
by placing it upside down. (About 0.2 US
oz (7cm
3
) of fork oil will be left in the fork
assembly when it is left inverted for about 20
minutes at 20°C (68°F).)
(1)
(1) fork assembly
To properly dispose of drained fluids, refer to You
& the Environment (page 151).
NOTICE
Improper disposal of drained fluids is harmful to
the environment.
2. Tighten the fork center bolt lock nut (2) fully
and measure the thread length (A) as shown.
Standard: 0.4 – 0.5 in (11 – 13 mm)
Wipe the oil completely off the fork damper.
(2)
(A)
(2) fork center bolt lock nut
(A) thread length
3. Blow out the oil completely off the fork
spring (3) using the compressed air. Install
the fork spring. Install the fork damper
assembly (4) to the fork assembly (1).
(4)
(3)
(1)
(1) fork assembly
(3) fork spr
ing
(4) fork damper assembly
Amount of fork oil left in the fork
(without damper and spring) unit: cm
3
minute
°
C/
°
F
30/86
20/68
10/50
0/32
5
7.1
10.6
11.8
12.9
10
5.9
8.2
8.3
10.6
20
4.7
7.1
7.2
9.4
35
4.2
5.9
6.2
8.2
55
3.5
5.6
5.8
7.9
85
3.5
4.7
4.9
7.1
145
3.5
4.7
4.8
5.9
(cm
3
)
17CRF450X31MEY710.indb120 2016/06/0811:46:14
Adjustments for Competition 121
Front Suspension Adjustments
4. Place the lower end (axle holder) of the slider
in a vise with a piece of wood or soft jaws to
avoid to damage.
NOTICE
Over-tightening the vise can damage the axle
holder.
5. Push out the fork damper piston rod from the
axle holder of the slider by pushing the fork
damper.
Apply pressure to the fork damper and insert
the piston base (5) or mechanic's stopper tool
between the axle holder and fork center bolt
lock nut (2).
Measure the thread length again.
Standard: 0.4 – 0.5 in (11 – 13 mm)
6. Install the push rod (6) into the fork damper
piston rod until it stops.
Check the push rod installation by turning the
push rod right and left.
7. Apply fork oil to a new O-ring (7) and install
it to the fork center bolt (8). Install the fork
center bolt to the fork damper piston rod
aligning the adjusting rod (9) with the push
rod. Tighten the fork center bolt fully by
hand.
(8)
(7)
(9)
(5)
(2)
(6)
(2) fork center bolt lock nut (7) O-ring
(5) piston base (8) f
ork center bolt
(6) push rod (9) adjusting rod
8. Measure the length of the fork center
bolt lock nut (2) and fork center bolt (8)
clearance.
Standard: 0.06 – 0.08 in (1.5 – 2.0 mm)
If the clearance is out of specification, check
the fork center bolt lock nut and fork center bolt
installation.
(2)
(8)
(2) fork center bolt lock nut
(8) fork cent
er bolt
9. Tighten the fork center bolt lock nut (2)
to the fork center bolt (8) closely by hand.
Tighten the fork center bolt lock nut to the
specified torque:
16 Ibf·ft (22 N·m, 2.2 kgf·m)
(8)
(2)
(2) fork center bolt lock nut
(8) fork cent
er bolt
10. Remove the piston base or mechanic's stopper
tool while pushing to the fork damper. Apply
locking agent to the fork center bolt threads.
Install the fork center bolt (8) to the axle
holder and tighten it to the specified torque:
51 Ibf·ft (69 N·m, 7.0 kgf·m)
(8)
(8) fork center bolt
11. Measure the length (10) between the axle
holder and outer tube.
Standard: 12.5 ± 0.1 in (317 ± 2 mm)
12. Compare the length at assembly and at
disassembly. They should be the same length.
If the length at assembly is longer than at
disassembly, check the fork center bolt and lock
nut installation.
(10)
(10) length
(cont’d)
17CRF450X31MEY710.indb121 2016/06/0811:46:16
122 Adjustments for Competition
Optional Stiffer 27.47 lbf/in (4.81 N/mm) Fork Spring
Standard oil
capacity
11.1 US oz
(327 cm
3
)
Maximum oil
capacity
13.7 US oz
(405 cm
3
)
Slightly stiffer as
it nears full
compression.
Slightly softer as
it nears full
compression.
Minimum oil
capacity
10.5 US oz
(309 cm
3
)
3 scribe mar ks
Be sure the oil capacity is the same in both fork
legs.
Front Suspension Adjustments
13. Pour the recommended fork oil (11) into the
fork assembly (1).
Recommended Oil:
Pro Honda HP Fork Oil 5 W or equivalent.
(1)
(11)
(1) fork assembly
(11) for
k oil
Fork Oil Capacity:
Standard 26.32 lbf/in (4.61 N/mm) Fork Spring
Standard oil
capacity
11.0 US oz
(324 cm
3
)
Maximum oil
capacity
13.6 US oz
(402 cm
3
)
Slightly stiffer as
it nears full
compression.
Slightly softer as
it nears full
compression.
Minimum oil
capacity
10.3 US oz
(306 cm
3
)
Optional Softer 25.18 lbf/in (4.41 N/mm) Fork Spring
Standard oil
capacity
11.2 US oz
(330 cm
3
)
Maximum oil
capacity
13.8 US oz
(407 cm
3
)
Slightly stiffer as
it nears full
compression.
Slightly softer as
it nears full
compression.
Minimum oil
capacity
10.5 US oz
(311 cm
3
)
No mark
(factory products)
2 scribe mar ks
1 scribe mar k
(aftermarket parts)
or
17CRF450X31MEY710.indb122 2016/06/0811:46:16
Adjustments for Competition 123
Front Suspension Adjustments
14. Check that the O-ring (12) on the fork
damper assembly (4) is in good condition.
Apply the recommended fork oil to the O-
ring.
15. Pull up the fork assembly (1) slowly and
install the fork damper assembly into the
outer tube.
(1)
(4)
(12)
(1) fork assembly
(4) for
k damper assembly
(12) O-ring
16. Insert both fork legs into the fork clamps.
Tighten the fork bridge lower pinch bolts (13)
to the specified torque:
15 Ibf·ft (20 N·m, 2.0 kgf·m)
(13)
(13) fork bridge lower pinch bolts
17. Tighten the fork damper (14) to the specified
torque using a lock nut wrench (15).
Actual:
25 Ibf·ft (34 N·m, 3.5 kgf·m)
Torque wrench scale reading:
23 Ibf·ft (31 N·m, 3.2 kgf·m), using a 20 in
(50 cm) long torque wrench.
When using a lock nut wrench, use a 20 in (50
cm) long deflecting beam type torque wrench.
The lock nut wrench increases the torque
wrench’s leverage, so the torque wrench reading
will be less than the torque actually applied to the
fork damper.
(15)
(14)
(14) fork damper
(15) lock n
ut wrench
18. For ease of releasing air pressure after the
forks are installed, loosen the fork bridge
lower pinch bolts and position the outer tubes
so that the fork air pressure release screws
(16) are in front of the compression damping
adjusters (17).
Align (18) the top of the outer tube (19) with
the top surface of the fork top bridge (20).
(16)
(17)
(18)
(20)
(19)
(16) fork air pressure release screw
(17) compression damping adjuster
(18) align
(19) outer tube
(20) fork top bridge
19. Tighten the fork bridge lower pinch bolts (13)
to the specified torque:
15 Ibf·ft (20 N·m, 2.0 kgf·m)
20. Tighten the fork bridge upper pinch bolts (21)
to the specified torque:
16 Ibf·ft (22 N·m, 2.2 kgf·m)
NOTICE
Over-tightening the pinch bolts can deform
the outer tubes. Deformed outer tubes must be
replaced.
(13)
(21)
(13) fork bridge lower pinch bolts
(21) fork br
idge upper pinch bolts
(cont’d)
17CRF450X31MEY710.indb123 2016/06/0811:46:17
124 Adjustments for Competition
(34)
(32)
(33)
(35)
(32) front wheel (34) O-ring
(33) align (35) front axle shaft
26. Install and tighten the front axle nut (36) to
the specified torque.
65 Ibf·ft (88 N·m, 9.0 kgf·m)
Tighten the left axle pinch bolts (37) to the
specified torque.
15 Ibf·ft (20 N·m, 2.0 kgf·m)
(36)
(37)
(36) front axle nut
(37) left axle pinch bolts
Front Suspension Adjustments
21. Clean the threads of the fork protector bolts
(22) and axle holder thoroughly.
Apply locking agent to the fork protector bolt
threads.
Install the fork protectors (23), fork protector
bolts, brake hose clamp bolts (24) and
tripmeter cable clamp screws (25). Tighten
the fork protector bolts to the specified
torque:
5.2 Ibf·ft (7 N·m, 0.7 kgf·m)
Tighten tripmeter cable clamp screws to the
specified torque:
0.5 Ibf·ft (0.7 N·m, 0.1 kgf·m)
22. Align the brake caliper (26) and hose with the
let fork leg, making sure that the brake hose
is not twisted. An improperly routed brake
hose may rupture and cause a loss of braking
efficiency.
23. Clean the threads of the brake caliper
mounting bolts (27) and brake caliper
thoroughly. Apply locking agent to the bolt
threads. Install the brake caliper on the slider
and tighten the caliper mounting bolts to the
specified torque:
22 Ibf·ft (30 N·m, 3.1 kgf·m)
(26)
(27)
(24)
(25)
(23)
(27)
(22)
(22)
(22) fork protector bolts
(23) fork pr
otectors
(24) brake hose clamp bolts
(25) tripmeter cable clamp screws
(26) brake caliper
(27) brake caliper mounting bolts
24. Check the left side collar (28) and tripmeter
gear box (29) for wear or damage.
Apply grease to the dust seal lips.
Install the left side collar to the left wheel hub.
Install the tripmeter gear box while aligning
its tabs (30) of the tripmeter gear box with
the grooves (31) on the right wheel hub.
(28)
(29)
(31)
(30)
(28) left side collar (30) tabs
(29) tripmeter gear bo
x (31) grooves
25. Clean the clamping surface of the axle shaft
and axle holders.
Install the front wheel (32) between the fork
legs while inserting the disc between the
pads, and align (33) the tab of the tripmeter
gear box as shown.
Check that the tripmeter gear box O-ring (34)
is in good condition, replace it if necessary.
Apply a thin layer of grease to the front axle
shaft (35) and insert the front axle shaft from
the right side.
17CRF450X31MEY710.indb124 2016/06/0811:46:18
Adjustments for Competition 125
Front Suspension Adjustments
27. Install the handlebar (38), mounting rubbers
(39), washers and handlebar lower holder
nuts (40) and tighten the handlebar lower
holder nuts to the specified torque:
32 Ibf·ft (44 N·m, 4.5 kgf·m)
(38)
(40)
(39)
(38) handlebar
(39) mounting rubber
s
(40) washers/handlebar lower holder nuts
28. With the front brake applied, pump the fork
up and down several times to seat the axle
and check front brake operation.
29. While keeping the forks parallel, alternately
tighten the right axle pinch bolts (41) to the
specified torque:
15 Ibf·ft (20 N·m, 2.0 kgf·m)
NOTICE
To avoid damage when torquing the axle pinch
bolts, be sure the axle is seated firmly onto the
right fork leg clamp inner surface.
30. Connect the tripmeter cable (42) and tighten
the lock nut securely.
(41)
(42)
(41) right axle pinch bolts
(42) tripmeter cable
31. Install the disc cover (43) and tighten the disc
cover bolts (44) to the specified torque:
10 Ibf·ft (13 N·m, 1.3 kgf·m)
(43)
(44)
(43) disc cover
(44) disc cover bolts
32. Turn the rebound damping (45) and
compression damping (46) adjuster back to
their original settings.
(45)
(46)
(45) rebound damping adjuster
(46) compression damping adjuster
33. Install the steering damper (page 101) and
handlebar pad.
17CRF450X31MEY710.indb125 2016/06/0811:46:18
126 Adjustments for Competition
Rear Suspension Adjustments
Each turn of the adjuster changes spring length
and spring pre-load. One turn equals: spring
length/spring pre-load:
0.06 in (1.5 mm)/18.18 lbf (80.85 N)
Pin spanners should be used for turning the shock
spring lock nut and adjusting nut. See page 169
for optional pin spanners.
Spring pre-load length (Standard spring)
Standard: 10.16 in (258.0 mm)
Min.: 9.80 in (249.0 mm)
Spring pre-load length (Optional spring)
Min. (Softer, 296.9 lbf/in (52.0 N/mm)):
9.9 in (251 mm)
Min. (Stiffer, 319.2 lbf/in (55.9 N/mm)):
9.9 in (251 mm)
The rear suspension can be adjusted for the
rider’s weight and riding conditions by changing
the spring pre-load and the rebound and
compression damping.
The rear shock absorber assembly includes a
damper unit that contains high pressure nitrogen
gas. Do not attempt to disassemble, service,
or dispose of the damper; see your dealer. The
instructions found in this owner’s manual are
limited to adjustments of the shock assembly
only.
Puncture or exposure to flame may also result in
an explosion, causing serious injury.
Service or disposal should only be done by your
dealer or a qualified mechanic, equipped with
the proper tools, safety equipment and the Honda
Service Manual.
If your CRF is new, put enough part-throttle
break-in time (about 1 hour) on it to ensure that
the suspension has worked in.
Rear Suspension Spring Pre-Load
Pre-load should be adjusted when the engine
is cold because it is necessary to remove the
muffler (page 62).
Optional pin spanners are available for turning
the lock nut and adjusting nut to adjust spring
pre-load.
1. Place your CRF on an optional workstand or
equivalent support with the rear wheel off the
ground.
2. Lift the subframe to the upright position
(page 39).
3. Check that the spring pre-load is adjusted to
the standard length. Adjust as necessary by
loosening the shock spring lock nut (1) and
turning the adjusting nut (2).
Each complete turn of the adjusting nut
changes the spring length by 0.06 in (1.5
mm).
4. After adjustment, hold the adjusting nut
and tighten the shock spring lock nut to the
specified torque:
32 lbf·ft (44 N·m, 4.5 kgf·m)
(1)
(2)
(3)
(4)
(1) shock spring lock nut (3) pin spanners
(2) adjusting nut
(4) spring length
To increase spring pre-load:
Loosen the shock spring lock nut with the
optional pin spanners (3) and turn the adjusting
nut to shorten the spring length (4). Do not
shorten to less than:
9.80 in (249.0 mm)
To decrease spring pre-load:
Loosen the shock spring lock nut with the
optional pin spanners (3) and turn the adjusting
nut to increase the spring length (4). Do not
increase to more than:
10.20 in (259.0 mm)
17CRF450X31MEY710.indb126 2016/06/0811:46:19
Adjustments for Competition 127
Rear Suspension Adjustments
Rear Suspension Damping
Compression Damping
Compression damping may be adjusted in two
stages with separate adjusters.
The high speed compression damping adjuster
(1) is effective when compression damping
adjustment is desired for high speed operation.
The low speed compression damping adjuster
(2) should be used when compression damping
adjustment is desired at relatively low speeds.
• Both the high and low speed compression
damping can be increased by turning the
appropriate adjuster clockwise.
• Adjust the high speed compression damping
adjuster in 1/12 turn increments.
• Be sure the low speed compression damping
adjuster is firmly located in a detent, and not
between positions.
(1)
(2)
(1) high speed compression damping adjuster
(2) low speed compression damping adjust
er
High Speed Compression Damping:
The high speed compression damping can be
adjusted by turning the hexagonal portion of the
compression adjuster.
The high speed compression damping adjuster
has 3-1/2 turns or more.
To adjust to the standard position:
1. Turn the adjuster clockwise until it will no
longer turn (lightly seats). This is the full
hard setting.
2. Turn the adjuster counterclockwise 7/12 –
1-1/12 turns and the punch marks are aligned.
Low Speed Compression Damping:
The low speed compression damping can be
adjusted by turning the center screw of the
compression adjuster.
The low speed compression damping adjuster has
13 positions or more.
Turning the adjuster one full turn clockwise
advances the adjuster 4 positions.
To adjust to the standard position:
1. Turn the adjuster clockwise until it will no
longer turn (lightly seat). This is the full hard
setting.
2. Turn the adjuster counterclockwise 10 clicks
and the punch marks are aligned.
Rebound Damping
The rebound damping adjuster (1) is located at
the lower end of the shock absorber.
It has 17 positions or more. Turning the adjuster
one full turn advances the adjuster 4 positions.
• Rebound damping can be increased by turning
the adjuster clockwise.
• Be sure that the rebound damping adjuster is
firmly located in a detent, and not between
positions.
1
(1)
(1) rebound damping adjuster
To adjust to the standard position:
1. Turn the adjuster clockwise until it will no
longer turn (lightly seat). This is the full hard
position.
2. Turn the adjuster counterclockwise 10 – 13
clicks with the punch marks on the adjuster
and the shock absorber aligned.
17CRF450X31MEY710.indb127 2016/06/0811:46:20
128 Adjustments for Competition
UNLOADED MEASUREMENT
(without rider)
EXAMPLE: 23.6 in (600 mm)
REAR FENDER MOUNTING BOLT
CHAIN ADJUSTER LOCK NUT
3. Measure the loaded with rider dimension.
Remove the workstand. With two helpers
available, sit as far forward as possible on
your CRF’s seat, wearing your riding apparel.
Ask one helper to steady your CRF perfectly
upright so you can put both feet on the pegs.
Bounce your weight on the seat a couple of
times to help the suspension overcome any
situation and settle to a good reference point.
Ask the other helper to measure the loaded
with rider dimension.
LOADED
(with rider)
EXAMPLE: 19.7 in (500 mm)
REAR FENDER MOUNTING BOLT
CHAIN ADJUSTER LOCK NUT
Example:
Unloaded = 23.6 in (600 mm)
– Loaded = 19.7 in (500 mm)
Race Sag = 3.9 in (100 mm)
Rear Suspension Adjustments
4. Calculate the race sag dimension.
To do this, subtract the loaded with rider
dimension (step 3) from the unloaded
dimension (step 2).
Standard Race Sag: 3.9 in (100 mm)
Adjust spring pre-load as necessary to obtain
the desired handling results. Decreasing the
race sag dimension (example: 3.5 in, 90 mm)
improves turning ability for tight terrain
at the cost of slightly reduced straight line
stability.
Increasing the race sag dimension (example:
4.3 in, 110 mm) may improve stability
on faster terrain with less turns, but will
reduce turning performance slightly and
may upset the balance between the front and
rear suspension, producing a harsher ride.
This will happen if the adjustment shifts
the effective wheel travel toward the more
progressive end of its range.
5. Measure the loaded without rider dimension.
Do this with your CRF set at the standard
race sag.
BIKE LOADED
(without rider)
EXAMPLE: 21.7 in (550 mm)
Example:
Unloaded = 23.6 in (600 mm)
– Loaded = 21.7 in (550 mm)
Sag = 2.0 in (50 mm)
(Without Rider)
Rear Suspension Race Sag
Setting the proper race sag (ride height) is very
important for competition use.
Race sag refers to the amount of rear wheel travel
used by your CRF at rest, ready to ride, with you
on the seat. As a general rule of thumb, the race
sag dimension should be about one-third of the
maximum travel.
On your CRF, ride height is changed by adjusting
the rear suspension spring pre-load.
Spring Pre-load & Race Sag Adjustment
The following adjustment procedure establishes
the correct starting point for any suspension
tuning — the proper rear spring pre-load
adjustment for your specific needs.
Your CRF should be at normal racing weight,
including fuel and transmission oil. You should
be wearing all your normal protective apparel.
You will need two helpers.
To calculate the proper adjustment, it is necessary
to measure between two fixed points — from
the center of the rear fender mounting bolt to the
center of the chain adjuster lock nut as illustrated
here — for three different situations:
unloaded: motorcycle on an optional workstand
with rear suspension fully extended, no rider.
loaded with rider: motorcycle on ground, with
rider.
loaded without rider: motorcycle on ground,
without rider.
1. Support your CRF on an optional workstand
or equivalent with the rear wheel off the
ground.
2. Measure the unloaded dimension.
17CRF450X31MEY710.indb128 2016/06/0811:46:20
Adjustments for Competition 129
Rear Suspension Adjustments
Because of the great absorption quality of the
shock bumper rubber, it may be difficult for
you to notice when your CRF’s suspension is
bottoming. Some riders may think the damping
or perhaps the leverage ratio is too harsh. In
reality, the problem is most likely insufficient
spring pre-load or a spring that is too soft. Either
situation prevents utilizing the full travel.
Keep in mind that a properly adjusted suspension
system may bottom slightly every few minutes at
full speed. Adjusting the suspension to avoid this
occasional bottoming may cost more in overall
suspension performance than it is worth.
A spring that is too stiff for your weight will not
allow the rear tire to hook up under acceleration
and will pass more bumps on to you.
6. Calculate the free sag dimension.
To do this, subtract the loaded without
rider dimension (step 5) from the unloaded
dimension (step 2).
Free sag indicates the distance your rear
suspension should sag from the weight of the
sprung portion of your CRF.
With the spring pre-load set to obtain the
proper race sag, the rear suspension should
sag 0.4 to 1.0 in (10 to 25 mm).
If the rear of your CRF sags less than 0.4 in
(10 mm) from its own weight, the spring is
too stiff for your weight. It is not compressed
enough, even though you have the proper
race sag adjustment. As a result, the rear
suspension will not extend as far as it should.
Spring Rates
If you are lighter or heavier than the average rider
and cannot set the proper ride height without
altering the correct spring pre-load, consider an
aftermarket shock absorber spring.
A spring that is too soft for your weight forces
you to add excessive spring pre-load to get the
right race sag and, as a result, the rear end of
the motorcycle is raised. This can cause the rear
wheel to unload too much in the air and top out
as travel rebounds. The rear end may top out
from light braking, or kick sideways over lips and
square-edged terrain. It may even top-out when
you dismount your CRF.
17CRF450X31MEY710.indb129 2016/06/0811:46:20
130 Adjustments for Competition
Suspension Adjustments for Track Conditions
Soft Surface
On soft ground, sand, and especially mud,
consider increasing compression damping front
and rear.
Sand often requires a bit more rebound damping
to minimize rear end kick. Although sand bumps
are usually larger, there’s more distance between
them, giving the shock more time to recover.
You may want a little bit stiffer front suspension
for sand tracks to help keep the front end up and
improve straight-line stability.
In a muddy event, stiffer aftermarket springs
front and rear may help, especially if you are
heavier than the average rider. Your CRF may
be undersprung because of the added weight of
the clinging mud. This additional weight may
compress the suspension too much and affect
traction.
Hard Surface
For a fast, hard track with no large jumps, you
can probably run the same spring as normal, but
run softer damping both ways-compression and
rebound. If you run softer rebound damping, the
wheel will follow the rough ground and small
bumps much better, and you will hook up better.
With a lot of rebound damping, the wheel returns
very slowly and doesn’t contact the ground
quickly enough after each bump. The result is a
loss of traction and slower lap times.
17CRF450X31MEY710.indb130 2016/06/0811:46:20
Adjustments for Competition 131
Suspension Adjustment Guidelines
Follow the procedures described below to accurately adjust your CRF, using the methods described on pages 112 – 130. Remember to make all adjustments in
one-click or 1/12 turn increments. Test ride after each adjustment.
Front Suspension Adjustment
Adjustments for Type of Track
Hard-surfaced track Begin with the standard setting. If the suspension is too stiff/soft, adjust according to the chart below.
Sand track Adjust to a stiffer position.
Example: – Turn the compression damping adjuster to a stiffer position.
– Install the optional stiff spring. (Adjust compression damping to a softer position and rebound damping to a stiffer position at
this time.)
Mud track Adjust to a stiffer position because mud build-up increases your CRF’s weight
Example: – Turn the compression damping adjuster to a stiffer setting.
– Install the optional stiff spring.
Adjustments for Too Soft/Stiff Damping
Symptom Action
Soft suspension Initial travel too soft:
• Steering is too quick.
• Front end darts while cornering or riding in a straight line.
– Test stiffer compression damping adjustments in one-click increments.
– Test stiffer rebound damping in one-click increments.
Middle travel too soft:
• Front end dives when cornering.
If suspension isn’t stiff in initial travel:
– Test stiffer compression damping adjustments in one-click increments.
If initial travel becomes stiff because of the above adjustment:
– Reduce the rebound damping in one-click increments.
– Test softer compression damping adjustments in one-click increments.
If that doesn’t solve the problem, install the optional stiff spring.
Final travel too soft:
• Bottoms on landings.
• Bottoms on large bumps, especially downhill bumps.
If initial and middle travel aren’t stiff:
– Test stiffer compression damping adjustments in one-click increments.
If initial and middle travel are stiff:
– Install the optional stiff spring.
If initial travel is stiff after installing the optional stiff spring:
– Test soft compression damping adjustments in one-click increments.
If initial travel is still soft after installing the optional stiff spring:
– Test stiffer compression damping adjustments in one-click increments.
If nal travel is still soft after installing the optional stiff spring:
– Increase the fork oil capacity in increments of 0.2 US oz (5 cm
3
).
Entire travel too soft:
• Front end shakes.
• Fork bottoms over any type of terrain.
– Install the optional stiff spring.
– Test stiffer compression damping adjustments in one-click increments.
– Increase rebound damping in one-click increments.
17CRF450X31MEY710.indb131 2016/06/0811:46:20
132 Adjustments for Competition
Suspension Adjustment Guidelines
Symptom Action
Stiff suspension Initial travel too stiff:
•
Stiff on small bumps while riding at full throttle in a straight line.
• Stiff on small cornering bumps.
• Front end wanders while riding at full throttle in a straight line.
– Test softer compression damping adjustments in one-click increments.
– Reduce the rebound damping adjustments in one-click increments.
– Check for dirt in the dust seals. Check the fork oil for any contamination.
If the front end dives while cornering, reduce the rebound damping in one click
increments. If that doesn’t solve the problem, install the optional stiff spring.
If the stiff spring makes the suspension too stiff over the full range of travel:
– Test softer compression damping adjustments in one-click increments until the
desired compression damping for initial travel is obtained.
Middle travel too stiff:
• Stiff on bumps when cornering.
• Front end wanders when cornering.
• Stiff suspension on bumps, especially downhill bumps.
• While braking, front end dives during initial travel, then feels stiff.
If initial travel isn’t stiff:
– Test stiffer compression damping adjustments in one-click increments. (This
should produce smooth fork action from initial to middle travel.)
If initial and middle travel is stiff:
– Test softer compression damping adjustments in one-click increments.
– Reduce the rebound damping in one-click increments.
Final travel too stiff:
• Doesn’t bottom on landings, but feels stiff.
• Stiff on large bumps, especially downhill bumps.
• Stiff on large bumps when cornering.
If initial and middle travel aren’t stiff:
– Test stiffer compression damping adjustments in one-click increments. (This
should produce smooth fork action from initial to middle travel.)
If nal travel is still stiff after the above adjustment, or
If initial and middle travel becomes stiff:
– Install the optional soft spring.
– Test softer compression damping adjustments in one-click increments.
If the entire travel feels stiff after the above adjustment:
– Test softer compression damping adjustments in one-click increments until the
desired initial travel compression damping is obtained.
– Lower the oil capacity by 0.2 US oz (5 cm
3
).
Entire travel too stiff:
• Stiff suspension on any type of terrain.
– Test softer compression damping adjustments in one-click increments.
– Reduce the rebound damping in one-click increments.
– Lower the oil capacity by 0.2 US oz (5 cm
3
).
17CRF450X31MEY710.indb132 2016/06/0811:46:21
Adjustments for Competition 133
Suspension Adjustment Guidelines
Rear Suspension Adjustment
Adjustments for Type of Track
Hard-surfaced track Begin with the standard settings. If the suspension is too stiff/soft, adjust according to the chart below.
Sand track Lower the rear end (to improve front wheel stability) by increasing Race Sag (reduce spring pre-load).
Example: – Turn the compression damping adjuster and, especially, rebound damping adjuster to a stiffer setting.
– Increase standard Race Sag (+0.2 to 0.4 in/5 to 10 mm).
Mud track Adjust to a stiffer position because mud build-up increases your CRF’s weight.
Example: – Adjust the compression and rebound damping adjusters to stiffer settings.
– Install the optional stiff spring.
– Reduce standard Race Sag (–0.2 to 0.4 in/–5 to 10 mm).
Symptoms and Adjustment
• Always begin with the standard settings.
• Turn the low speed compression and rebound damping adjusters in one-click increments, and the high speed compression damping adjuster in 1/12 turn increments at a
time. Adjusting two or more clicks or turns at a time may cause you to pass over the best adjustment. Test ride after each adjustment.
• If, after setting, the suspension feels unusual, nd the corresponding symptom in the table and test stiffer or softer compression and/or rebound damping adjustments until the
correct settings are obtained as described.
Symptom Action
Stiff suspension Suspension feels stiff on small
bumps
1. Test softer low speed compression adjustment.
2. If it still feels stiff, further test softer low and high speed compression adjustments simultaneously.
Suspension feels stiff on large
bumps
1. Test softer high speed compression adjustment.
2. If it still feels stiff, further test softer low and high speed compression adjustments simultaneously.
Entire travel too stiff 1. Test softer high and low speed compression adjustments and rebound adjustment simultaneously.
2. If it still feels stiff, replace the spring with a softer spring (optional) and begin with the standard settings to
softer settings.
Soft suspension Entire travel too soft 1. Test stiffer high and low speed compression adjustments simultaneously.
2. If it still feels soft, replace the spring with a stiffer spring (optional) and begin with the standard settings to
stiffer setting.
Rear end sways 1. Test stiffer high and low speed compression adjustments and rebound adjustment to stiffer settings
simultaneously.
Suspension
bottoms
Suspension bottoms at landing
after jumping
1. Test stiffer high speed compression adjustment.
2. If it still bottoms, test stiffer high and low speed compression adjustments, and replace the spring with a stiffer
spring (optional) if necessary.
Suspension bottoms after landing 1. Test stiffer low speed compression adjustment.
2. If it still bottoms, test stiffer high and low speed compression adjustments, and replace the spring with a stiffer
spring (optional) if necessary.
Suspension bottoms after end of
continuous bumps
1. Test softer rebound dumping adjustment.
2. If it still bottoms, test stiffer high and low speed compression adjustments and softer rebound damping
adjustment, and replace the spring with a stiffer spring (optional) if necessary.
17CRF450X31MEY710.indb133 2016/06/0811:46:21
134 Adjustments for Competition
Carburetor Adjustment & Tuning Tips
The carburetor used on your CRF will seldom
experience trouble with the standard settings
under average load, and average climatic and
barometric conditions. However, to fine-tune the
engine’s power output, the carburetor may require
specific adjustments for competition use.
However, in order to comply with emission
regulations, we recommend that you make no
carburetor changes unless you use your CRF for
competition only.
Carburetor Components
Cold Start Circuit
A very rich mixture must be delivered to the
cylinder when a cold engine is being started.
When the choke knob (1) is pulled out, fuel is
metered by the starter jet (2) and is mixed with
air from the air passage (3) (located above the
throttle valve (4)) to provide a rich mixture for
starting. The mixture discharges through the
orifice (5) into the cylinder.
(2)
(5)
(1)
(3)
(4)
(1) choke knob (4) throttle valve
(2) start
er jet (5) ori ce
(3) air passage
Hot Start Circuit
A lean mixture must be delivered to the cylinder
when a hot engine is being started. When the hot
start lever is pulled back, the hot start valve (1)
opens, allowing air to be supplied to the main
bore (2) through the hot start air passage (3). This
extra air enters the air-fuel mixture from the slow
circuit resulting in a lean condition.
(1)
(3)
(2)
(1) hot start valve
(2) main bore
(3) hot star
t air passage
17CRF450X31MEY710.indb134 2016/06/0811:46:21
Adjustments for Competition 135
Carburetor Adjustment & Tuning Tips
Accelerator Pump Circuit
The accelerator pump circuit operates when
the throttle is opened. As the throttle valve (1)
opens, the pump rod (2) depress the diaphragm
(3). At this time, the inlet check valve (4) is shut
resulting in a sharp increase in pressure in the
pump chamber (5). The outlet check valve (6)
then opens, supplying fuel to the main bore via
the accelerator nozzle (7).
(7)
(1)
(6)
(2)
(3)
(4)
(5)
(1) throttle valve (5) pump chamber
(2) pump rod
(6) outlet check valve
(3) diaphragm (7) accelerator nozzle
(4) inlet check valve
Slow Circuit
Fuel is metered by the slow jet (1) and mixed
with air from the air passage (2). The mixture
enters the venturi through the bypass (3) and
pilot outlet (4) that has been metered by the pilot
screw (5).
(3)
(2)
(1)
(5)
(4)
(1) slow jet (4) pilot outlet
(2) air passage (5) pilot screw
(3) bypass
Main Circuit
Fuel is metered by the main jet (1), jet needle
(2) and needle jet (3). It is then mixed with air
coming from the air jet (4) and enters the venturi
past the needle jet.
Baffle Plate
The baffle plate (5) prevents foaming of fuel or
abnormal fuel level around the main jet.
Float Bowl
The float (6) and float valve (7) operate to
maintain a constant level of fuel in the float bowl.
(2)
(4)
(7)
(6)
(5)
(3)
(1)
(1) main jet (5) baffle plate
(2) jet needle (6) oat
(3) needle jet
(7) oat valve
(4) air jet
17CRF450X31MEY710.indb135 2016/06/0811:46:21
136 Adjustments for Competition
Carburetor Adjustment & Tuning Tips
Carburetor Removal
1. Turn the fuel valve OFF.
2. Raise the rear wheel off the ground by placing an
optional workstand or equivalent under the engine.
3. Remove the seat and fuel tank (pages 36, 37).
4. Remove the muffler (page 62).
5. Lift the subframe to the upright position (page 39).
6. Drain the remaining fuel in the float bowl by
loosening the carburetor drain screw (1).
Gasoline is highly ammable and
explosive. You can be burned or seriously
injured when handling fuel.
• Stop the engine and keep heat, sparks
and ame away.
• Handle fuel only outdoors.
• Wipe up spills immediately.
WARNING
Drain the carburetor into an approved gasoline
container and dispose of it in an approved
manner (page 151).
NOTICE
Improper disposal of drained fluids is harmful to
the environment.
(1)
(1) carburetor drain screw
7. Tighten the carburetor drain screw.
8. Remove the shock absorber upper mounting
nut (2) and bolt (3).
(3)
(2)
(2) shock absorber upper mounting nut
(3) shock absorber upper mounting bolt
9. Disconnect the throttle position sensor
connector (4).
(4)
(4) throttle position sensor connector
10. Loosen the insulator band screw (5) and
remove the carburetor (6) from the insulator
(7).
(5) (7)
(6)
(5) insulator band screw
(6) carburet
or
(7) insulator
11. Loosen the hot start cable nut (8) and remove
the hot start valve (9) from the carburetor.
(9)
(8)
(8) hot start cable nut
(9) hot start v
alve
17CRF450X31MEY710.indb136 2016/06/0811:46:21
Adjustments for Competition 137
Carburetor Adjustment & Tuning Tips
Carburetor Disassembly
1. Pull up the cable clamp (1).
2. Remove the carburetor top cover bolts (2),
cable clamp and carburetor top cover (3).
(2)
(1)
(3)
(1) cable clamp
(2) carburet
or top cover bolts
(3) carburetor top cover
3. Remove the jet needle/holder assembly (4)
from the throttle valve (5).
(5)
(4)
(5)
(4)
(4) jet needle/holder assembly
(5) throttle v
alve
12. Remove the throttle drum cover bolt (10) and
throttle drum cover (11).
(11)
(10)
(10) throttle drum cover bolt
(11) throt
tle drum cover
13. Loosen the throttle cable lock nut (12),
adjuster (13), throttle cable bolt (14) and
disconnect the throttle cables (15) from the
throttle drum (16).
(16)
(12)
(14)
(13)
(15)
(12) throttle cable lock nut (15) throttle cables
(13) adjuster
(16) throttle drum
(14) throttle cable bolt
(cont’d)
4. Remove the link arm torx screw (6) and
throttle valve (5).
When installing the link arm torx screw,
apply a locking agent to the link arm torx
screw threads.
(5)
(6)
(5) throttle valve
(6) link arm torx scr
ew
5. Remove the throttle valve roller (7) and
floating valve (8).
(5)
(7)
(8)
(7) throttle valve roller
(8) oating val
ve
17CRF450X31MEY710.indb137 2016/06/0811:46:22
138 Adjustments for Competition
Carburetor Adjustment & Tuning Tips
When installing the floating valve (8) onto
the throttle valve (5) make sure the floating
valve’s flat side faces out and the hole (9)
faces down.
(5)
(8)
(9)
(5) throttle valve
(8) oating val
ve
(9) hole
6. Remove the accelerator pump cover screws
(10) and accelerator pump cover (11).
(11)
(10)
(10) accelerator pump cover screws
(11) accelerator pump cover
7. Remove the U-ring (12), O-ring (13), spring
(14) and diaphragm (15).
Clean the diaphragm.
When installing the U-ring into the accelerator
pump cover (11) make sure the U-ring flat-side
faces down, away from the float bowl (16).
(12)
(11)
(16)
(15)
(12)
(14)
(13)
(11) accelerator pump cover (14) spring
(12) U-r
ing (15) diaphragm
(13) O-ring (16) oat bowl
8. Remove the holder screw (17), throttle stop
screw holder (18), float bowl screws (19),
tube guides (20) and float bowl (16).
(17)
(19)
(16)
(18)
(20)
(16) oat bowl
(17) holder scr
ew
(18) throttle stop screw holder
(19) oat bowl screws
(20) tube guides
9. Remove the pump rod (21).
Clean the pump rod and rod passage (22).
Install the pump rod by pushing the rod
forcibly into the link lever (23) until it snaps
into place.
(22)
(21)
(23)
(21)
(23)
(21) pump rod
(22) rod passage
(23) link lev
er
17CRF450X31MEY710.indb138 2016/06/0811:46:22
Adjustments for Competition 139
Carburetor Adjustment & Tuning Tips
10. Measure the float level (24) with the float
level gauge (25) during float tab is just
contacting the float valve and the carburetor
intake (26) facing up. The float level should
be 0.31 in (8.0 mm).
If the float level is out of specification, adjust
it by bending the float tab carefully.
(26)
(25)
(24)
(24) oat level
(25)
oat level gauge
(26) carburetor intake
11. Remove the leak jet (27) and O-ring (28)
from the float bowl (16).
Clean the leak jet.
(28)
(27)
(16)
(16) oat bowl
(27) leak jet
(28) O-ring
Carburetor Assembly
To assemble, reverse the disassembly procedures.
To install the carburetor, reverse the removal
procedures.
Tighten the following parts to the specified
torque.
leak jet:
0.2 lbf·ft (0.3 N·m, 0.03 kgf·m)
float bowl screws:
1.5 lbf·ft (2.1 N·m, 0.2 kgf·m)
accelerator pump cover screws:
1.5 lbf·ft (2.1 N·m, 0.2 kgf·m)
carburetor top cover bolts:
1.5 lbf·ft (2.1 N·m, 0.2 kgf·m)
jet needle/holder assembly:
1.5 lbf·ft (2.1 N·m, 0.2 kgf·m)
link arm torx screw:
1.5 lbf·ft (2.1 N·m, 0.2 kgf·m)
throttle drum cover bolt:
2.5 lbf·ft (3.4 N·m, 0.3 kgf·m)
hot start cable nut:
1.5 lbf·ft (2.1 N·m, 0.2 kgf·m)
throttle cable lock nut:
3.0 lbf·ft (4.0 N·m, 0.4 kgf·m)
throttle cable bolt:
3.0 lbf·ft (4.0 N·m, 0.4 kgf·m)
shock absorber upper mounting nut:
32 lbf·ft (44 N·m, 4.5 kgf·m)
• Tighten the insulator band screw (1) so the
insulator band distance is 0.5 ± 0.04 in (12 ±
1 mm).
• Route the throttle cables (2), hot start cable
(3) and throttle position sensor wire correctly.
• After installing the carburetor, adjust the
throttle grip freeplay and hot start lever
freeplay.
• After installing the carburetor, check the
throttle position sensor connector (4) for
correct routing.
• After installing the carburetor, check the
air vent hoses (5) and overflow hose (6) for
kinking or pinching and correct routing.
• After connecting the fuel line (7), check the
fuel line clamps (8) as illustrated. (next page)
• Check that the U-ring and O-ring are in good
condition. Replace them if necessary.
(1)
0.5 ± 0.04 in
(12 ± 1 mm)
(1) insulator band screw
(4)
(3)
(2)
(2) throttle cables
(3) hot start cab
le
(4) throttle position sensor connector
17CRF450X31MEY710.indb139 2016/06/0811:46:24
140 Adjustments for Competition
(6)
(5)
(5)
(8)
(7)
(6)
(8)
0 – 0.1 in (0 – 3 mm)
(5)
(5) air vent hoses
(6) over o
w hose
(7) fuel line
(8) fuel line clamps
Carburetor Adjustment & Tuning Tips
Idle Speed Adjustment
1. If the engine is cold, start it and warm it up 3
minutes. Then shut it off.
2. Connect a tachometer to the engine.
3. Shift the transmission into neutral. Start the
engine.
4. Keep the motorcycle in an upright position.
5. Adjust idle speed with the throttle stop screw
(1).
Idle speed:
1,700 ± 100 rpm
(1)
(1) throttle stop screw
17CRF450X31MEY710.indb140 2016/06/0811:46:25
Adjustments for Competition 141
Steering Damper Adjustment
The steering damper adjuster (1) has 11 positions
or more. Turning the adjuster one full turn
clockwise advances the adjuster six positions.
To adjust the adjuster to the standard setting,
proceed as follows:
Turn the adjuster clockwise until it will no longer
turn (lightly seats). This is the full hard position.
The adjuster is set in the standard position when
the adjuster is turned counterclockwise 9 clicks.
Damping can be increased by turning the adjuster
clockwise.
NOTICE
Always start with full hard when adjusting
damping.
Do not turn the adjuster more than the given
positions or the adjuster may be damaged.
Be sure that the steering damper adjuster is
firmly located in a detent, and not between
positions.
(1)
(1) steering damper adjuster
Steering Damper Adjustment
The steering damper can be adjusted for riding
conditions by using following method:
• Damping – Turning the steering damper
adjuster adjusts how quickly the steering
damper extends or compresses.
17CRF450X31MEY710.indb141 2016/06/0811:46:25
142 Adjustments for Competition
Follow the procedures described below to accurately adjust your CRF, using the methods described on this page.
Symptoms and Adjustment
• Always begin with the standard settings.
• Turn the steering damper adjuster in one-click increments at a time. Adjusting two or more clicks at a time may cause you to pass over the best adjustment.
Test ride after each adjustment.
Symptom Action
Steering is wobbling on large bumps Adjust the steering damper adjuster to stiffer setting.
Steering is wobbling at sand track Adjust the steering damper adjuster to stiffer setting.
Steering is heavy when cornering Adjust the steering damper adjuster to softer setting.
Steering Damper Adjustment Guidelines
17CRF450X31MEY710.indb142 2016/06/0811:46:25
Adjustments for Competition 143
Chassis Adjustments
The following suggestions may improve a
specific concern. Subtle changes in overall
handling may also be noted.
Rear End
If you have a problem with rear wheel traction,
raise the rear end of your CRF by increasing the
rear spring pre-load. Instead of running 3.9 in
(100 mm) of sag, you can run 3.5 in (90 mm) so
the rear of the bike will sit a little higher. This
should produce more traction because of the
change to the swingarm and location of your
CRF’s center of gravity.
If you have a problem with the steering head
shaking when you use the front brake hard or if
your CRF wants to turn too quickly, lower the
rear of the motorcycle by reducing the rear spring
pre-load. This will increase fork rake and trail
and should improve stability in a straight line.
The effective suspension travel will be transferred
toward the firmer end of wheel travel.
Keep the race sag adjustment (page 128) in the
3.5 – 4.3 in (90 – 110 mm) range.
Fork Height/Angle
Standard Position
The position of the outer tubes in the clamps is
not adjustable. Align the top of outer tube (1)
with the top of upper fork clamp (2).
(STANDARD POSITON)
Wheelbase
Adjusting your CRF’s wheelbase can offer subtle
changes in overall handling. You may adjust
wheelbase by adding or removing links on the
drive chain. If you change the wheelbase, be sure
to recheck the race sag and adjust, if necessary.
In the past, a general rule was lengthen the
wheelbase to add straight line stability, shorten
the wheelbase to improve turning. However, we
suggest you do not lengthen the wheelbase of
your CRF unless you are racing on a track with
more fast sections than normal.
As a general recommendation, keep the
wheelbase as short as possible. This positions
the wheels closer together, improves turning
response, increases weighting (traction) on the
rear wheel, and lightens weighting on the front
wheel.
With your CRF, you will probably find that the
standard setting or a shorter wheelbase will offer
more overall benefits.
(1)
(2)
(3)
(1) top of outer tube
(2) upper fork clamp
(3) standard position
0 in (0 mm)
17CRF450X31MEY710.indb143 2016/06/0811:46:25
144 Adjustments for Competition
Gearing
You can “adjust” the power delivery of the
standard engine to suit track conditions by
changing gearing. This allows you to utilize a
different portion of the engine’s power range at a
given throttle setting. New gearing may provide
the change you are looking for without the need
to consider further modifications.
The portion of your engine’s power range you
use can be adjusted by changing the final drive
ratio with different sized driven sprockets.
Gearing changes allow you to more closely
match the type of terrain and the available
traction. Normally, a change of one tooth on the
driven sprocket will be sufficient.
There is a choice of both higher and lower final
drive ratios with two optional driven sprockets.
Like the optional springs, these sprockets are
listed in the Optional Parts List section of this
manual (page 169).
Unless you have the required mechanical
knowhow, tools, and an official Honda Service
Manual, sprocket changing should be done by
your dealer.
Higher Gearing (less driven sprocket teeth)
• increases top speed in each gear (provided the
engine will pull the higher gearing)
• reduces frequency of shifting (wider gear
ratios)
• reduces engine rpm at a given throttle setting
or ground speed (which may allow better rear
wheel traction on slippery or loose terrain)
However:
• the engine may not pull the higher gearing
• the spacing between gears may be too wide
• engine rpm may be too low
Lower Gearing (more driven sprocket teeth)
• decrease top speed in each gear
• increases frequency of shifting (narrower gear
ratios)
• increases engine rpm at a given throttle
setting or ground speed (which may provide
more power-to-the-ground on good traction
surfaces)
However:
• spacing between gears may be too narrow
• engine rpm may be too high
Some tracks may be watered heavily prior to the
first race, then lightly or not at all during the day.
This results in a track surface that is slippery
during the first few races, then changes from
good to great and back to good and possibly
ends the day with a slick rock-hard consistency.
Ideally, your gearing should be adjusted to suit
all these conditions.
• Wet and slippery or sandy conditions: use
a higher gear (less teeth) to keep engine
rpm down, and avoid unwanted wheelspin.
The engine may bog in certain corners so
you’ll need to slip the clutch to compensate;
downshifting may be too drastic a change in
speed.
• Average conditions: use the standard sprocket.
• Hard (but not slippery) track conditions: use
lower gearing (more teeth) to keep the engine
rpm high where the engine produces the most
power. This may require an extra upshift on
certain sections or perhaps you can just rev it
out a bit longer.
For tight tracks, consider lower gearing to avoid
having to slip the clutch frequently. Repeated
fanning or pulling of the clutch lever in a turn
to raise engine rpm may eventually damage the
clutch system.
A gearing change may help for riding in sand,
where you want to keep the front end light so it
can float from the peak of one sand whoop to the
next. Generally, with higher gearing, it is easier
to maintain that perfect attitude (maximum rear
wheel traction and a light front end) because you
remain in the powerband longer in each gear.
The higher gearing allows you to steer more
efficiently with throttle control and body English.
If you are riding a track with sections where you
choose to over-rev the engine temporarily rather
than shifting up, higher gearing might help.
Sometimes you have to sacrifice performance on
one section of the track to gain a better overall
time. Your goal is the fastest overall lap time,
even if the cost is some sections where the
gearing feels wrong.
If you decide to try a gearing change, have
someone check your times with a stopwatch
(before and after the change) to get an accurate
appraisal of the change. “Seat-of-the-pants”
feelings can’t be trusted. Eliminating wheelspin
with a gearing change can make you feel like
you’re going slower when, in reality, you’ve
decreased your time by increasing your speed
with better traction.
These gearing recommendations should be
evaluated by considering your ability, your riding
style, and the track.
17CRF450X31MEY710.indb144 2016/06/0811:46:25
Adjustments for Competition 145
Tire Selection for Track Conditions
Choosing the correct tire tread pattern and rubber
compound can affect your placing in competition.
The tires on your CRF offer a “happy medium”
for the variety of soil conditions the majority of
riders are likely to encounter.
Experienced competitors often switch to tires
developed for specific terrain conditions. If you
do switch, stay with the factory recommended
sizes. Other tires may affect handling or
acceleration.
Be aware that tire sizes (width and aspect ratio)
do vary from manufacturer to manufacturer
or even among tires made by the same
manufacturer. Variations in tires, especially
the sidewall profile, can change the attitude of
your CRF and its handling. Tire variations that
raise or lower the rear of your CRF have a more
significant effect on handling than variations in
front tires which, generally, don’t vary as much.
Often, you can see or feel the change in tire
size. Another way to check is to measure the
rolling circumference of the old and new tires.
A higher profile tire will have a larger rolling
circumference.
If you do switch to tires designed for special
terrain use, remember they will be less acceptable
in other circumstances. For example, an
aggressive mud tire will give excellent grip on
wet, loamy terrain, but less impressive grip on a
hard surface.
If you choose a tire with a sticky compound for
added traction, remember that it may transfer
additional loads to the transmission because it
grips so well, especially when riding in situations
that normally place unusual demands on the
transmission.
Complete consumer information can be obtained
from the various tire manufacturer representatives
and dealers.
Some general recommendations for specific
terrain follow:
Hard, Slick Soil
Use tires with many relatively short knobs that
are close together in order to obtain the largest
possible contact patch on the surface. The rubber
compound needs to be softer for hard ground in
order to hook up, but not so soft that the knobs
roll over easily and affect holding a straight
line. These tires tend to wear more quickly than
standard tires because of the combination of soft
rubber and hard terrain.
Muddy Soil
Use a more open tread pattern to avoid clogging.
For these conditions, the relatively long knobs
will probably be made from a harder rubber
compound to reduce any tendency to bend back
under acceleration or wear quickly.
Loose, Sandy Soil
Use a tire that is similar in construction to those
needed for tacky soil and mud, but with a few
more knobs.
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146 Adjustments for Competition
Personal Fit Adjustments
The following suggestions may make your ride
both more comfortable and more responsive to
your control input.
Control Positioning
• Position the control levers so that you can use
them comfortably when seated and standing.
• Adjust the mounting bolt torque of the clutch
and brake lever assemblies so that they
can rotate on the handlebar in a fall. If an
assembly does not rotate, it may bend or break
a control lever. Make sure that the bolts are
torqued securely enough to prevent slippage
during normal operation.
Apply Pro Honda Hondalock or an equivalent to
the threads of these bolts prior to adjustment to
help ensure the correct torque is retained. Tighten
the top bolts first.
(1)
(1)
(1) control lever mounting bolts
As an alternative, consider wrapping the
handlebar area under the control assemblies with
teflon tape. Then tighten the assemblies to their
normal torque. Upon impact, the fully-tightened
assemblies should rotate on the teflon tape.
• Position the shift lever and brake pedal so
they are close to your boot for rapid access,
but not so close that either is depressed when
sitting or standing comfortably on your CRF.
Handlebar Position, Width & Shape
• Position the handlebar so that both gripping
the bar and operating the controls is
comfortable while both seated and standing,
while riding straight ahead and turning.
Tighten the forward bolts first.
• The handlebar position may be moved
rearward either 0.1 in (3 mm) (using optional
handlebar lower holders) or 0.2 in (6 mm) (by
rotating the standard holders 180 degrees).
Refer to the Service Manual for installation
instructions. Be sure to check control
cable and wiring harness routing after the
adjustment.
• Handlebar width can be trimmed with
a hacksaw to better suit your particular
shoulder width and riding preference. Think
this through carefully and cutoff just a small
amount at a time from both sides equally. It is
obviously much easier to make the handlebar
narrower than it is to add material.
• Chamfer the edges to remove burrs and other
irregularities or roughness after sawing the
handlebar.
• An alternate handlebar shape, through varying
rise or rearward sweep dimensions, will
provide further adjustment to riding position
and may better suit your particular body
size or riding style. Each of the ergonomic
dimensions of the machine were determined
to suit the greatest possible number of riders
based on an average size rider.
17CRF450X31MEY710.indb146 2016/06/0811:46:26
Tips 147
Tips
Here’s helpful advice on how to transport
and store your Honda, as well as three
troubleshooting flow charts.
Transporting Your Motorcycle .........................148
Storing Your Honda .........................................149
Preparation for Storage ...............................149
Removal from Storage ................................150
You & the Environment ...................................151
Troubleshooting ...............................................152
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148 Tips
Transporting Your Motorcycle
If you use a truck or motorcycle trailer to
transport your Honda, we recommend that you
follow these guidelines:
• Use a loading ramp.
• Make sure the fuel valve is off.
• Secure the motorcycle in an upright position,
using motorcycle tie-down straps. Avoid
using rope, which can loosen and allow the
motorcycle to fall over.
To secure your CRF, brace the front wheel
against the front of the truck bed or trailer rail.
Attach the lower ends of two straps to the tie-
down hooks on your CRF. Attach the upper ends
of the straps to the handlebar (one on the right
side, the other on the left), close to the fork.
Check that the tie-down straps do not contact any
control cables or electrical wiring.
Tighten both straps until the front suspension is
compressed about half-way. Too much pressure is
unnecessary and could damage the fork seals.
Use another tie-down strap to keep the rear of the
motorcycle from moving.
We recommend that you do not transport your
CRF on its side. This can damage the motorcycle,
and leaking gasoline could be a hazard.
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Tips 149
Storing Your Honda
Gasoline is highly ammable and
explosive. You can be burned or seriously
injured when handling fuel.
• Stop the engine and keep heat, sparks
and ame away.
• Handle fuel only outdoors.
• Wipe up spills immediately.
WARNING
5. Remove the right engine guard bolt (1) and
right engine guard (2).
Remove the center engine guard mounting
bolts, collars (3) and center engine guard (4).
(1)
(2)
(4)
(3)
(3)
(3)
(1) right engine guard bolt
(2) right engine guard
(3) center engine guard mounting bolts/collars
(4) center engine guard
6. Remove the radiator cap and coolant drain
bolt/sealing washer (5) at the water pump (6)
to drain coolant.
After the coolant has been completely
drained, ensure that the drain bolt sealing
washer is in good condition and reinstall the
drain bolt and radiator cap.
Coolant drain bolt:
7 lbf·ft (10 N·m, 1.0 kgf·m)
(5)
(6)
(5) coolant drain bolt/sealing washer
(6) water pump
7. Remove the reserve tank cap (7).
Disconnect the siphon hose (8) from the
reserve tank (9).
Pull out the reserve tank from the frame and
drain the reserve tank coolant.
Empty the reserve tank coolant and rinse the
inside of the reserve tank with water.
(7)
(9)
(8)
(7) reserve tank cap
(8) siphon hose
(9) reserv
e tank
8. Reinstall the reserve tank and reserve tank
cap and connect the siphon hose.
If you won’t be riding for an extended period,
such as during the winter, thoroughly inspect
your Honda and correct any problem before
storing it. That way, needed repairs won’t be
forgotten and it will be easier to get your CRF
running again.
To reduce or prevent deterioration that can
occur during storage, also follow the following
procedures.
Preparation for Storage
1. Completely clean all parts of your CRF. If
your CRF has been exposed to sea air or salt
water, wash it down with fresh water and
wipe dry.
2. Change the engine oil and filter (page 44).
3. Change the transmission oil (page 47).
4. Drain the fuel tank and carburetor into an
approved gasoline container.
Turn the fuel valve OFF and loosen the
carburetor drain screw. Drain gasoline into an
approved container. Retighten the carburetor
drain screw.
(cont’d)
17CRF450X31MEY710.indb149 2016/06/0811:46:26
150 Tips
Storing Your Honda
11. Remove the battery and charge it fully.
Store in an area protected from freezing
temperatures and direct sunlight. Slow charge
the battery (page 105) once a month.
12. Inflate the tires to their recommended
pressures (page 93).
13. Place your CRF on an optional workstand or
equivalent to raise both tires off the ground.
14. Stuff a rag into the muffler outlet. Then tie
a plastic bag over the end of the muffler to
prevent moisture from entering.
15. Store your CRF in an unheated area, free
of dampness, away from sunlight, with a
minimum of daily temperature variation.
16. Cover your CRF with a porous material.
Avoid using plastic or similar non-breathing,
coated materials that restrict air flow and
allow heat and moisture to accumulate.
Removal from Storage
1. Uncover and clean your CRF.
Change the engine and transmission oil if
more than 4 months have passed since the
start of storage (pages 44, 47).
2. Uncover the end of the muffler and remove
the rag from the muffler outlet.
3. Fill the fuel tank with recommended fuel
(page 41).
4. Charge the battery (page 105) as required.
Install the battery.
5. Pour a fresh recommended coolant mixture
(page 48) slowly into the radiator filler hole
up to the filler neck.
Capacity:
1.53 US qt (1.45 ℓ)
After disassembly
1.28 US qt (1.21 ℓ)
After draining
Remove the radiator reserve tank cap and fill
the reserve tank to the upper level line.
Bleed air from the system (page 50).
6. Perform all maintenance checks (page 11).
9. Install the center engine guard (4) while
aligning its tabs (10) with the grooves (11) of
the radiator reserve tank.
Install the center engine guard mounting bolts
and collars (3), then tighten them. Install the
right engine guard (2) and tighten the right
engine guard bolt (1).
(11)
(4)
(1)
(2)
(10)
(3)
(3)
(3)
(1) right engine guard bolt
(2) right engine guard
(3) center engine guard mounting bolts/collars
(4) center engine guard
(10) tabs
(11) grooves
10. Lubricate the drive chain (page 98).
17CRF450X31MEY710.indb150 2016/06/0811:46:26
Tips 151
You & the Environment
Owning and riding a motorcycle can be
enjoyable, but you must do your part to protect
nature. When you show respect for the land,
wildlife, and other people, you also help preserve
the sport of off-road riding.
Following are tips on how you can be an
environmentally responsible motorcycle owner.
• Choose Sensible Cleaners. Use a
biodegradable detergent when you wash
your CRF. Avoid aerosol spray cleaners that
contain chlorofluorocarbons (CFCs) which
damage the atmosphere’s protective ozone
layer. Don’t throw cleaning solvents away; see
the following guidelines for proper disposal.
• Recycle Wastes. It’s illegal and thoughtless to
put used engine oil in the trash, down a drain,
or on the ground. Used oil, gasoline, and
cleaning solvents contain poisons that can hurt
refuse workers and contaminate our drinking
water, lakes, rivers, and oceans.
Before changing your oil, make sure you have
the proper containers. Put oil and other toxic
wastes in separate sealed containers and take
them to a recycling center. Call your local or
state office of public works or environmental
services to find a recycling center in your area
and get instructions on how to dispose of
non-recyclable wastes.
NOTICE
Improper disposal of drained fluids is harmful to
the environment.
17CRF450X31MEY710.indb151 2016/06/0811:46:26
152 Tips
Troubleshooting
The items that are serviceable using this Manual
are followed by the page number reference
in parenthesis. The items that require use of
the Honda Service Manual are followed by an
asterisk (*).
POOR PERFORMANCE AT LOW AND UNSTABLE
IDLE SPEED
CHECK POSSIBLE CAUSES
1. Check if air
cleaner is over-
oiled (P.51)
CORRECT
INCORRECT
INCORRECT
LEAKING
CLOGGED
INCORRECT
LOW
WEAK OR
INTERMITTENT
SPARK
CORRECT
CORRECT
NOT LEAKING
NOT CLOGGED
GOOD SPARK
2. Check if the
connecting tube
and/or insulator
is leaking
3. Check carburetor
pilot screw
adjustment
*
4. Check carburetor
jets and accelerator
pump for clogs
5. Try spark test
*
6. Check the throttle
position sensor
*
CORRECT
7. Test cylinder
compression
*
• Over-oiled air cleaner
• Loose connecting
tube and/or insulator
band
• Damaged connecting
tube and/or insulator
• Improper pilot screw
adjustment
*
•
Contaminants in the fuel
• Not cleaned
frequently enough
(P.137)
• Faulty throttle position
sensor
*
• Ring worn
• Cylinder worn or
damaged
*
• Piston worn or
damaged
*
• Head gasket not
sealing
• Valve stuck open
•
Faulty, carbon or wet
fouled spark plug (P.61)
• Faulty ignition control
module
*
• Faulty exciter coil
*
• Faulty ignition coil
*
• Broken or shorted
spark plug wire
• Faulty ignition pulse
generator
*
•
Loose or disconnected
ignition system wires
• Faulty engine stop
button
ENGINE DOES NOT START OR IS HARD TO START
CHECK POSSIBLE CAUSES
1. Check the fuel
flow to carburetor
REACHING
CARBURETOR
NOT REACHING
CARBURETOR
WEAK OR NO
SPARK
LOW
ENGINE STARTS
BUT SOON STOPS
2. Try spark test*
GOOD SPARK
• No fuel in fuel tank
• Clogged fuel line or
fuel filter (P.42)
• Sticking float valve
*
• Clogged fuel fill cap
breather tube (P.41)
• Faulty spark plug (P.61)
•
Fouled spark plug (P.61)
• Faulty ignition control
module
*
• Broken or shorted
spark plug wire
• Faulty exciter coil
*
• Broken or shorted
ignition coil
• Faulty engine stop
button
• Loose or disconnected
ignition system wires
• Faulty ignition pulse
generator
*
3. Test cylinder
compression
*
CORRECT
• Valve stuck open
• Worn cylinder and
piston ring
*
• Leaking/damaged
cylinder head gasket
• Improper valve timing
*
• Seized valve
4. Start by following
normal starting
procedure
ENGINE DOES
NOT FIRE
• Improper choke
operation
• Pilot screw incorrectly
adjusted
*
• Insulator leaking
•
Improper ignition timing
(Faulty ignition coil or
ignition pulse generator)
*
• Fuel contaminated
• Improper hot start
operation (P.60)
WET PLUG
5. Remove and
inspect spark plug
DRY
• Carburetor flooded
• Choke closed
• Throttle valve open
• Air cleaner dirty (P.51)
6. START WITH CHOKE ON
POOR PERFORMANCE AT HIGH SPEED
CHECK POSSIBLE CAUSES
1. Disconnect fuel
line at carburetor
and check for
clogging (P.41)
UNRESTRICTED
FUEL FLOW
FUEL FLOW
RESTRICTED
DIRTY
2. Remove air
cleaner (P.51)
AIR CLEANER
NOT DIRTY
• Lack of fuel in tank
(P.41)
• Clogged fuel line
(P.41)
• Clogged fuel fill
cap breather tube
(P.41)
• Clogged fuel valve
(P.41)
• Clogged fuel filter
(P.42)
• Not cleaned
frequently enough
(P.51)
CLOGGED
INCORRECT
LOW
WEAK OR
INTERMITTENT
SPARK
NOT CLOGGED
CORRECT
CORRECT
GOOD SPARK
3. Check carburetor
jets for clogging
4. Check valve
timing
5. Try spark test
*
6. Test cylinder
compression
*
• Contaminants in
the fuel
• Cam sprocket not
installed properly
•Faulty, carbon or wet
fouled spark plug
(P.61)
•Faulty ignition control
module
*
•Faulty exciter coil
*
•Faulty ignition coil
*
•Broken or shorted
spark plug wire
•Faulty ignition pulse
generator
*
• Loose or
disconnected
ignition system wires
•Faulty engine stop
button
•Ring worn
• Cylinder worn or
damaged
*
•Piston worn or
damaged
*
•Head gasket not
sealing
•Improper valve
timing
*
•Valve stuck open
17CRF450X31MEY710.indb152 2016/06/0811:46:27
Taking Care of the Unexpected 153
Taking Care of the Unexpected
This section gives practical advice to help you
solve problems.
If a Fuse Blows ................................................ 154
If Your Battery Is Low (or Dead)..................... 155
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154 Taking Care of the Unexpected
If a Fuse Blows
All of the electrical circuits on your CRF have
a fuse to protect them from damage caused by
excess current flow (short circuit or overload).
If something electrical on your CRF stops
working, the first thing you should check for
is a blown fuse. Check the fuse before looking
elsewhere for another possible cause of the
problem. Replace a blown fuse and check
component operation.
• The main fuse (and spare) are located on the
starter motor magnetic switch behind the left
side cover.
Recommended Main Fuse: 15A
1. To prevent an accidental short circuit, stop
the engine.
2. Open the air cleaner housing cover by turning
the quick fastener (1) counterclockwise
and remove the left side cover bolt (2), seat
mounting bolt (3) and left side cover (4).
(1)
(2)
(3)
(4)
(1) quick fastener
(2) left side cov
er bolt
(3) seat mounting bolt
(4) left side cover
3. Remove the starter magnetic switch (5) with
the rubber case.
4. Disconnect the wire connector (6) of the
starter magnetic switch.
5. Pull out the main fuse (7). If it is blown (8),
install the spare main fuse (9).
(6)
(7)
(9)
(5)
(8)
(5) starter magnetic switch
(6) wire connector
(7) main fuse
(8) b
lown fuse
(9) spare main fuse
6. Reconnect the wire connector and install the
starter magnetic switch.
If you do not have a replacement fuse with the
proper rating for the circuit, install one with a
lower rating.
NOTICE
Replacing a fuse with one that has a higher
rating greatly increases the chance of damage to
the electrical system.
If you replace a blown fuse with a spare fuse
that has a lower rating, replace the fuse with the
correct rating as soon as you can. Also remember
to replace the spare fuse that was installed.
If the replacement fuse of the same rating burns
out in a short time, there is probably a serious
electrical problem on your CRF.
Leave the blown fuse in that circuit and have
your CRF checked by your dealer.
7. Install the left side cover and left side cover
bolt.
8. Close the air cleaner housing cover.
17CRF450X31MEY710.indb154 2016/06/0811:46:27
Taking Care of the Unexpected 155
If Your Battery Is Low (or Dead)
Jump-starting is not recommended, especially if
you use an automobile battery.
The greater amperage of an automobile battery
when the car engine is running can damage your
CRF’s electrical system.
Bump starting is also not recommended.
If you can’t charge the battery or it appears
unable to hold a charge, see your dealer.
17CRF450X31MEY710.indb155 2016/06/0811:46:27
156 Taking Care of the Unexpected
17CRF450X31MEY710.indb156 2016/06/0811:46:27
Blank page
Technical Information 157
Technical Information
This section contains dimensions, capacities, and
other technical data.
Vehicle Identification .......................................158
Specifications ...................................................159
Torque Specifications ....................................... 160
Emission Control Systems ...............................164
Oxygenated Fuels ............................................166
Competition Logbook ......................................167
Optional Parts List ...........................................169
Spare Parts & Equipment.................................170
Wiring Diagram ...............................................171
17CRF450X31MEY710.indb157 2016/06/0811:46:27
158 Technical Information
Vehicle Identification
Serial Numbers
The VIN and engine serial number are required
when you register your CRF. They may also be
required when ordering replacement parts. You
may record these numbers in the Quick Reference
section at the rear of the manual.
The VIN (1) is stamped on the right side of the
steering head.
RIGHT SIDE
(1)
(1) VIN
The engine number (2) is stamped on the left
crankcase.
LEFT SIDE
(2)
(2) engine number
17CRF450X31MEY710.indb158 2016/06/0811:46:27
Technical Information 159
Specifications
Overall length
Overall width
Overall height
Wheelbase
Seat height
Footpeg height
Ground clearance
Item English
85.8 in
32.3 in
50.2 in
58.5 in
37.9 in
17.0 in
13.6 in
Metric
Type
Dimension
Frame
Fork oil capacity
(except fork damper
per leg)
F. suspension
R. suspension
Tire size, front
F. brake, swept area
R. brake, swept area
Fuel recommendation
Fuel capacity
Caster angle
Trail length
Twin tube
Telescopic fork,
travel 11.0 in (279 mm)
stroke 12.4 in (315 mm)
Pro-link,
travel 12.3 in (313 mm)
80/100 – 21 51M
bias-ply, tube type
Single disc brake
51.8 in
2
(334.5 cm
2
)
Single disc brake
60.6 in
2
(391.1 cm
2
)
unleaded gasoline, pump
octane number of 91 or
higher
27 03
Tire pressure, front (cold)
15 psi (100 kPa, 1.0 kgf/cm
2
)
Tire pressure, rear (cold)
1.90 US gal
4.53 in
11.0 US oz 324 cm
3
115 mm
7. 2 ℓ
DUNLOP D742FA
Tire size, rear
Tire type
110/100 – 18 64M
DUNLOP D756
Fuel reserve capacity 0.42 US gal 1.6 ℓ
Item English
3.78 x 2.44 in
0.31 in
Cylinder arrangement
Bore and stroke
Displacement
Compression ratio
Engine oil capacity
After draining
After draining and
oil filter change
After disassembly
After disassembly
Transmission oil
capacity
After draining
Type
Identification number
Main jet
Jet needle
Piston valve
FCR13C
#145
NNEU
Slow jet
Pilot screw opening
Float level
Idle speed
Liquid cooled, 4-stroke
#45
1-1/8 turns out
1,700 ± 100 rpm
Type
Metric
0.67 ℓ
0.70 ℓ
0.87 ℓ
0.65 ℓ
0.75 ℓ
96.0 x 62.1
mm
8.0 mm
Engine
Carburetor
12.0 : 1
Valve clearance (cold)
Intake: 0.006 ± 0.001 in
(0.16 ± 0.03 mm)
Exhaust: 0.011 ± 0.001 in
(0.28 ± 0.03 mm)
Clutch type
Transmission
Primary reduction
Gear ratio I
Gear ratio II
Gear ratio III
Gear ratio IV
Gear ratio V
Final reduction
Item English Metric
Drive train
Electrical
Wet, multi-plate type
5-speed, constant mesh
2.739
2.230
1.625
1.235
1.000
0.826
3.923
NGK
DENSO
NGK
DENSO
Gear shift pattern
Ignition
Starting system
Spark plug : Standard
Optional
ICM
Electric, Kickstarter
Battery
YTZ7S
12V-6 Ah (10HR)
Light
Headlight 12V-35 W
Spark plug gap 0.039
–
0.043 in
(1.0
–
1.1 mm)
Fuse
Main fuse 15 A
Left foot-operated return
system 1-N-2-3-4-5
IFR8H11
VK24PRZ11
IFR9H11
VK27PRZ11
2,180 mm
820 mm
1,275 mm
1,485 mm
963 mm
431 mm
345 mm
27.4 cu-in
0.71 US qt
0.74 US qt
0.92 US qt
0.69 US qt
0.79 US qt
449 cm
3
After disassembly
Cooling system,
capacity
After draining
1.28 US qt (1.21 ℓ)
1.53 US qt (1.45 ℓ)
Single 6 inclined from
vertical
15 psi (100 kPa, 1.0 kgf/cm
2
)
17CRF450X31MEY710.indb159 2016/06/0811:46:27
160 Technical Information
Torque Specifications
Nuts, Bolts, Fasteners
Check and tighten nuts, bolts, and fasteners before every outing.
Engine
Item
1
2
3
4
5
6
7
8
9
10
11
12
13
Cylinder head cover bolts
Clutch cover bolts
Water pump cover bolts
Transmission oil check
bolt
Crankshaft hole cap
Oil filter cover bolts
Cylinder bolt
Cylinder head bolts
Exhaust pipe joint nuts
Drive sprocket bolt
Engine oil drain bolt
Transmission oil drain
bolt
Coolant drain bolt
Torque
Remarks
lbf
•
ft N
•
m kgf
•
m
7
7
7
7
11
7
7
7
15
23
12
12
7
10
10
10
10
15
10
10
10
21
31
16
16
10
1.0
1.0
1.0
1.0
1.5
1.0
1.0
1.0
2.1
3.2
1.6
1.6
1.0
1. UBS bolt.
2. Apply grease to the threads.
3. Apply oil to the threads and seating surface.
NOTES:
NOTE 1
NOTE 3
NOTE 3
NOTE 2
ENGINE
(1)
(9)
(5)
(4)
(2)
(3)
(13)
(8)
(10)
(7)
(12)
(11)
(6)
17CRF450X31MEY710.indb160 2016/06/0811:46:27
Technical Information 161
Torque Specifications
Frame
(14)
(15)
(14)
(19)
(13)
(21)
(1)
(2)
(5)
(6)
(3)
(4)
(7)
(9)
(8)
(17)
(18)
(11)
(10)
(20)
(12)
(13)
(21)
(16)
Item
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
Steering stem nut
Fork bridge upper pinch
bolts
Fork bridge lower pinch
bolts
Handlebar upper
holder bolts
Handlebar lower holder
nuts
Front axle nut
Axle pinch bolts
Rear axle nut
Chain adjuster lock nuts
Front engine hanger
nut
Middle engine hanger
nut
Engine hanger nut
Engine hanger plate bolts
Shock absorber (upper)
(lower)
Swingarm pivot nut
Fork (fork damper)
(fork cap assembly)
Rear shock arm nuts
(swingarm side)
(shock link side)
Rear shock link nuts
Shock spring lock nut
Kickstarter arm bolt
Shroud B bolts
FRAME
Torque
Remarks
lbf
•
ft
80
16
15
16
32
65
15
94
20
40
40
40
19
32
32
65
25
22
39
39
39
32
28
3.7
N
•
m
108
22
20
22
44
88
20
128
27
54
54
54
26
44
44
88
34
30
53
53
53
44
38
5
kgf
•
m
11.0
2.2
2.0
2.2
4.5
9.0
2.0
13.1
2.8
5.5
5.5
5.5
2.7
4.5
4.5
9.0
3.5
3.1
5.4
5.4
5.4
4.5
3.9
0.5
NOTE 1
NOTE 2
NOTE 1
NOTE 1
NOTE 1
NOTE 1, 6
NOTE 1, 6
NOTE 1, 6
1. U-nut.
2. UBS nut.
3. SH bolt.
4. Apply locking agent to the threads.
5. Alock bolt: replace with a new one.
6. Apply molybdenum oil to the threads and flange surface.
7. Apply a seizure inhibitor (Three Bond 1901 or equivalent)
to the bolt threads.
NOTES:
17CRF450X31MEY710.indb161 2016/06/0811:46:27
162 Technical Information
Torque Specifications
Frame
(36)
(26)
(27)
(39)
(32)
(43)
(42)
(33)
(23)
(29)
(30)
(31)
(28)
(22)
(43)
(40)
(41)
(25)
(24)
(37)
(31)
(30)
(34)
(35)
(38)
Item
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
Spark arrester mounting
bolts
Brake pedal adjuster
lock nut
Front brake master
cylinder holder bolts
Brake hose bolts
Front brake caliper
mounting bolts
Front brake disc nuts
Rear brake disc nuts
Brake pedal pivot bolt
Spokes (front)
(rear)
Rim locks
Subframe mounting
(upper)
bolts
(Iower)
Drive chain roller (upper)
(lower)
Fork center bolt
Fork center bolt lock nut
Disc cover bolts
Fork protector bolts
Tripmeter cable clamp
screws
Front brake hose guide
bolts
Muffler mounting
bolts (front)
(rear)
Muffler clamp bolt
Driven sprocket nuts
Seat mounting bolts
Torque
Remarks
lbf
•
ft N
•
m kgf
•
m
4.4
4.4
7.3
25
22
12
12
27
2.7
2.7
9
36
36
9
9
51
16
10
5.2
0.5
3.8
19
19
15
24
19
6
5.9
9.9
34
30
16
16
36
3.68
3.7
12
49
49
12
12
69
22
13
7
0.7
5.2
26
26
21
32
26
0.6
0.6
1.0
3.5
3.1
1.6
1.6
3.7
0.4
0.4
1.2
5.0
5.0
1.2
1.2
7.0
2.2
1.3
0.7
0.1
0.5
2.7
2.7
2.1
3.3
2.7
NOTE 7
NOTE 5
NOTE 1
NOTE 1
NOTE 3
NOTE 1
NOTE 4
NOTE 5
NOTE 1
1. U-nut.
2. UBS nut.
3. SH bolt.
4. Apply locking agent to the threads.
5. Alock bolt: replace with a new one.
6. Apply molybdenum oil to the threads and flange surface.
7. Apply a seizure inhibitor (Three Bond 1901 or equivalent)
to the bolt threads.
NOTES:
FRAME
17CRF450X31MEY710.indb162 2016/06/0811:46:28
Technical Information 163
Torque Specifications
Frame
(48)
(49)
(47)
(47)
(45)
(50)
(44)
(46)
Item
Front brake reservoir
cap screws
Rear brake reservoir
cap bolts
Fork air pressure release
screw
Right/left step bracket
mounting bolts (upper)
(lower)
Steering damper
mounting bolts
Fuel joint mounting bolts
Throttle cable adjuster
lock nuts
Torque
Remarks
lbf
•
ft N
•
m kgf
•
m
44
45
46
47
48
49
50
0.7
0.7
0.9
41
22
15
7
3.0
1
1
1.2
55
30
20
10
4
0.1
0.1
0.1
5.6
3.1
2.0
1.0
0.4
NOTE 5
1. U-nut.
2. UBS nut.
3. SH bolt.
4. Apply locking agent to the threads.
5. Alock bolt: replace with a new one.
6. Apply molybdenum oil to the threads and flange surface.
7. Apply a seizure inhibitor (Three Bond 1901 or equivalent)
to the bolt threads.
NOTES:
FRAME
17CRF450X31MEY710.indb163 2016/06/0811:46:28
164 Technical Information
Emission Control Systems
Exhaust Emission Requirements
The U.S. Environmental Protection Agency
(EPA), the California Air Resources Board
(CARB), and Environment Canada (EC) require
that your CRF comply with applicable exhaust
emissions standards during its useful life,
when operated and maintained according to the
instructions provided.
The vehicle emission control information label
(1) (2) is attached on the left side frame.
(1)
(2)
(1) vehicle emission control information label
(2) vehicle emission contr
ol information label
(Canada only)
Noise Emission Requirements
The EPA also requires that motorcycles built
after January 1,1983 comply with applicable
noise emission standards for one year or
1,865 miles (3,000 km) after the time of sale
to the ultimate purchaser, the time operated
and maintained according to the instructions
provided. (USA only)
Noise Emission Control System
TAMPERING WITH THE NOISE CONTROL
SYSTEM IS PROHIBITED: U.S. federal law
prohibits, or Canadian provincial laws may
prohibit the following acts or the causing thereof:
(1) The removal or rendering inoperative by any
person, other than for purposes of maintenance,
repair or replacement, of any device or element
of design incorporated into any new vehicle for
the purpose of noise control prior to its sale or
delivery to the ultimate purchaser or while it is
in use; or (2) the use of the vehicle after such
device or element of design has been removed or
rendered inoperative by any person.
AMONG THOSE ACTS PRESUMED TO
CONSTITUTE TAMPERING ARE THE
ACTS LISTED BELOW:
• Removal of, or puncturing the muffler, baffles,
header pipes, or any other component which
conducts exhaust gases.
• Removal of, or puncturing of any part of the
intake system.
• Lack of proper maintenance.
• Removing or disabling any emissions
compliance component, or replacing any
compliance component with a non-compliant
component.
Problems that May Affect Motorcycle
Emissions
If you are aware of any of the following
symptoms, have the vehicle inspected and
repaired by your dealer.
1. Hard starting or stalling after starting.
2. Rough idle.
3. Misfiring or backfiring during acceleration.
4. After-burning (backfiring).
5. Poor performance (driveability) and poor fuel
economy.
Federal regulations prohibit removing or
disabling a device or element of design that
may affect your engine’s emission performance
unless your CRF will be used exclusively in
competition. If you modify your engine for use in
sanctioned competition events, you must deface
or destroy the emission control information label.
17CRF450X31MEY710.indb164 2016/06/0811:46:28
Technical Information 165
Emission Control Systems
Source of Emission
The combustion process produces carbon
monoxide (CO), oxides of nitrogen (NOx), and
hydrocarbons (HC).
Control of hydrocarbons and oxides of nitrogen is
very important because, under certain conditions,
they react to form photochemical smog when
subjected to sunlight. Carbon monoxide does not
react in the same way, but it is toxic.
Honda Motor Co., Ltd. utilizes various systems
to reduce carbon monoxide, oxides of nitrogen
and hydrocarbons.
Exhaust Emission Control System
The exhaust emission control system is
composed of appropriate carburetor settings. No
adjustments should be made except for an idle
speed adjustment with the throttle stop screw.
The exhaust emission control system is separate
from the crankcase emission control system.
Secondary Air Injection System
The exhaust emission control system consists of
a secondary air injection system.
The secondary air injection system introduces
filtered air into the exhaust gases in the exhaust
port. The secondary air injection system helps
improve emission control performance.
No adjustments to this system should be made
although periodic inspection of the components is
recommended.
Crankcase Emission Control System
The engine is equipped with a closed crankcase
system to prevent discharging crankcase
emissions into the atmosphere.
Blow-by gas is returned to the combustion
muffler through the air cleaner and the carburetor.
Fuel Permeation Emission Control System
This vehicle complies with the Fuel Permeation
Emission Control regulations of the U.S.
Environmental Protection Agency (EPA), the
California Air Resources Board (CARB), and
Environment Canada (EC).
The fuel tank, fuel hoses, and fuel vapor charge
hoses used on this vehicle incorporate fuel
permeation control technologies.
Tampering with the fuel tank, fuel hoses, or
fuel vapor charge hoses to reduce or defeat the
effectiveness of the fuel permeation technologies
is prohibited by federal regulations.
17CRF450X31MEY710.indb165 2016/06/0811:46:28
166 Technical Information
Oxygenated Fuels
Some conventional gasolines are being
blended with alcohol or an ether compound.
These gasolines are collectively referred to as
oxygenated fuels. To meet clean air standards,
some areas of the United States and Canada use
oxygenated fuels to help reduce emissions.
If you use an oxygenated fuel, be sure it is
unleaded and meets the minimum octane rating
requirement.
Before using an oxygenated fuel, try to confirm
the fuel’s contents. Some states/provinces require
this information to be posted on the pump.
The following are the EPA-approved percentages
of oxygenates:
ETHANOL (ethyl or grain alcohol) up to 10% by
Volume
You may use gasoline containing up to 10%
ethanol by volume. Gasoline containing ethanol
may be marketed under the name “Gasohol.”
METHANOL (methyl or wood alcohol) up to 5%
by Volume
You may use gasoline containing methanol
containing up to 15% methanol by volume as
long as it contains cosolvents and corrosion
inhibitors to protect the fuel system. Gasoline
containing more than 5% methanol by volume
may cause starting and/or performance problems.
It may also damage metal, rubber, and plastic
parts of your fuel system.
If you notice any undesirable operating
symptoms, try another service station or switch
to another brand of gasoline.
Fuel system damage or performance problems
resulting from the use of an oxygenated fuel
containing more than the percentages of
oxygenates mentioned above are not covered
under warranty.
Oxygenated fuels can damage paint and plastic.
Be careful not to spill fuel when filling the fuel
tank. Wipe up any spills immediately.
NOTICE
Oxygenated fuels can damage paint and plastic.
17CRF450X31MEY710.indb166 2016/06/0811:46:29
Technical Information 167
Competition Logbook
Any serious competition effort relies heavily
on the knowledge gained and compiled from
previous racing events. The best way to organize
the many bits of information is to record them in
a logbook.
Your logbook can include such information
as suspension adjustments, gearing, and tire
selection. This detailed information, along with
your comments, can prove valuable when you
compete at the same track or on similar terrain.
Your logbook can also tell you when maintenance
was performed and when it will be necessary
again. Your logbook also lets you record any
repairs and lets you keep track of the running
time on the engine and suspension components.
If you choose to sell your CRF, the accurate
maintenance records in your logbook might be
the deciding deal-maker for a potential buyer.
Consider using different color pens or pencils to
record important information on specific subjects.
For example, record results in black, suspension/
chassis settings in blue, and gearing selections
in green. Color codes will help you identify the
information you want with a glance.
Tuning & Adjustment Records
Keep track of the settings and adjustments that
worked best at a particular location. These items
include:
• basic track conditions, altitude, and
temperature
• suspension settings
• chassis adjustments tested and selected
• gearing
• tire selection
• air pressure
Competition Records
• your placings
• thoughts to improve performance next time:
both yours and your CRF’s
• strategy notes
Maintenance Records
• regular interval maintenance
• repairs
• running time on engine
• running time on suspension components
Timekeeping
This Manual lists maintenance intervals for
every-so-many hours of running.
The most effective way to schedule maintenance
is by the hours you have run your CRF.
An official “guesstimate” is close enough for our
timekeeping purposes. You may choose to record
your time the same way aircraft operators do (but
without the benefit of an electrical hourmeter).
All running time is broken down into hours and
tenths of an hour (each six minutes represents
one tenth of an hour).
Racing Records
Information worth recording for this section of
your logbook may include:
• Your placing in each moto and overall
finishing position.
• Thoughts on what you could do to improve
your performance next time.
• Notes on any patterns noted in choice of
starting gate positions or in riding portions
of the course as the day progressed that may
prove helpful in future events.
• Any places on the course where you chose the
wrong line and were passed too easily.
• Notes on strategy used by your competition
or by riders in another event that are worth
remembering.
Maintenance Records
Regular maintenance items you’ll want to record
in your logbook should include:
• Dates and results of cylinder, piston and ring
examinations
• Patterns for frequency of need for
decarbonization with a particular oil
• When you last performed shock linkage and
swingarm pivot bearing maintenance
• Engine, transmission, and suspension oil
changes
• Chain, sprockets, chain guide and slider
replacements
• Coolant changes and related component
replacements
• Spark plug, brake pads and control cable
replacements
In addition, you should record any irregularities
noted in component wear so you’ll remember to
keep a close eye on these areas in the future.
17CRF450X31MEY710.indb167 2016/06/0811:46:29
168 Technical Information
Competition Logbook
Date Running Time Location/Event Comments (Suspension Settings, Gearing, Chassis Adjustments, Maintenance Performed, etc.)
(Make several photocopies of this page for future use)
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Technical Information 169
Optional Parts List
FRAME Remarks
Shock spring
Standard
Stiffer
Optional
Softer
Stiffer
Fork spring
Standard
Optional
Softer
The standard fork spring and shock spring
mounted on the motorcycle when it leaves the
factory are not marked. Before replacing the
springs, be sure to mark them so they can be
distinguished from other optional springs.
307.8 lbf/in (53.9 N/mm)
No mark
(factory products)
Red
paint
(aftermarket parts)
or
296.9 lbf/in (52.0 N/mm)
26.32 lbf/in (4.61 N/mm)
25.18 lbf/in (4.41 N/mm)
27.47 lbf/in (4.81 N/mm)
FRAME Remarks
Driven sprocket
Standard
< >: Drive chain links
51 Teeth, Aluminum.
<114>
Optional 50 Teeth, Aluminum
<114>
Optional no offset
52 Teeth, Aluminum
<116>
Handlebar
lower holder
Standard
3 mm offset
Red
Blue
319.2 lbf/in (55.9 N/mm)
Pink
These parts and tools may be ordered from your
dealer.
TOOLS Remarks
For checking tire air pressure
Pin spanner A
Workstand
To adjust spring pre-load.
(two spanners required)
For maintenance
Air gauge
Drive chain
size/link
DID520MXV/120
1 scribe mark
(aftermarket parts)
2 scribe marks
3 scribe marks
17CRF450X31MEY710.indb169 2016/06/0811:46:29
170 Technical Information
Spare Parts & Equipment
There are numerous spare parts you can take to
an event to help ensure you get in a full day of
riding. In addition to the usual nuts and bolts,
consider the following:
Spare Parts
spark plugs
shims
air cleaner (clean & oiled, sealed in a plastic bag)
chain & masterlink/plate
chain guide slider
chain slider
chain rollers
inner tubes (front & rear)
fenders
footpegs
front visor & side covers
handlebar
grips
levers (brake, clutch & hot start)
clutch lever handlebar mount
clutch cable
hot start cable
throttle assembly
throttle cable
shift lever
brake pedal
spokes (front & rear, each side)
sprockets (smaller than standard, for gearing
changes & collision damage replacement)
assorted nuts, bolts, washers, screws, cotter pins
headlight bulbs
battery
fuses
Additional Spares
front brake assembly
rear brake assembly
wheels & tires (front & rear, mounted)
clutch discs and plates
engine & transmission oil
seat
ignition components
radiator hoses
radiator shrouds (L & R)
brake hoses (front & rear)
General Tools
sockets (3/8 in drive)
screwdrivers: blade & Phillips No. 1, 2, 3
wrench, large adjustable
wrenches: open end & box
wrenches: hex (Allen)
wrench, spoke
torque wrench (metric scale, click-stop style)
pliers: standard, needle-nose, channel-lock set
hammer, plastic head
syringe with adjustable stop
tire pressure gauge
tire irons
tire pump or air tank
feeler gauge set
vernier caliper (metric)
pressure/vacuum testing equipment (USA only)
Honda Special Tools
Any special tools for your CRF purchased from
your dealer.
• Lock Nut Wrench 07WMA-KZ30100
• Tensioner Stopper 07AMG-001A100
• Spoke Wrench 07JMA-MR60100
• Piston Base 07958-2500001
Chemical Products
Pro Honda GN4 4-stroke Oil (Engine and
Transmission Oil)
SAE 80 or 90 gear oil
Pro Honda HP Fork Oil 5W
Pro Honda DOT4 Brake Fluid
Pro Honda HP Chain Lube
Pro Honda Foam Filter Oil
Pro Honda Hondabrite
Pro Honda Dielectric Grease
Pro Honda Handgrip Cement
Pro Honda Hondalock
Molybdenum disulfide grease (containing more
than 3% molybdenum disulfide additive)
Pro Honda White Lithium Grease
Multi-purpose Grease
Rust-inhibiting Oil
Cable lubricant
Pro Honda HP Coolant
Urea based multi-purpose grease designed for
high temperature, high pressure performance
(example: EXCELITE EP2 manufactured by
KYODO YUSHI, Japan or Shell Stamina EP2 or
equivalent)
Other Products
pliers-safety wire
safety wire
mechanic’s wire
duct tape
plastic tie-wraps
hose clamps
drop light
electrical tape
Scotch-Brite Hand Pad #7447 (maroon)
Teflon tape
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Technical Information 171
Wiring Diagram
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172 Technical Information
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Blank page
Consumer Information 173
Consumer Information
This section contains information about
contacting Honda and how to get an official
Honda service manual.
Authorized Manuals .........................................174
Warranty Coverage .......................................... 175
Warranty Service .............................................. 176
Contacting Honda ............................................177
Your Honda Dealer ..........................................178
The Honda Rider’s Club (USA only) ..............179
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174 Consumer Information
The Service Manual used by your authorized dealer is available from your
Honda dealer or Helm, Inc (USA only, Canada: See your dealer to order
authorized manuals.)
Also available, but not necessary to service your model, is the Honda
Common Service Manual, which explains basic service information for
various systems on Honda motorcycles, scooters, and ATV.
The Winter Storage Guide in conjunction with the Owner's Manual and
Service Manual can help you prepare your Honda motorcycle, scooter, ATV,
and SxS for winter storage.
These Honda manuals are written for the professional technician, but most
mechanically-capable owners should find them helpful if they have the proper
tools and skills. Special Honda tools are necessary for some procedures.
Publication Item No. Description
61MEY10 2017 CRF450X Service Manual
61CSM00 Common Service Manual
S9507 Winter Storage Guide
31MEY710 2017 CRF450X Owner’s Manual
Order On-Line: www.helminc.com
Order Toll Free: 1-888-CYCLE93 (1-888-292-5393)
(NOTE: For Credit Card Orders Only)
Monday - Friday 8:00 AM - 6:00 PM EST
Authorized Manuals
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Consumer Information 175
Warranty Coverage
• Emission Control System Warranty
• Noise Control Warranty (USA only)
Your new Honda is covered by certain warranties
as described in the Honda Motorcycle Warranties
Booklet that was provided to you by your Honda
dealer.
Please read this booklet and be aware of the
responsibilities, restrictions, and exclusions
which apply.
Please also keep your Honda owner’s card with
your Warranties Booklet.
Canada: Please refer to the Warranty Booklet
posted on our website at www.honda.ca.
It is important to realize that your warranty for
your Honda applies to defects in material or
factory workmanship. Your warranty coverage
does not apply to normal wear or deterioration
associated with using the motorcycle.
Your warranty coverage will not be voided if you
choose to perform your own maintenance.
However, you should have the proper tools
and service information and be mechanically
qualified. Failures that occur due directly to
improper maintenance or lack of maintenance are
not covered.
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176 Consumer Information
Warranty Service
Please remember that recommended maintenance
interval servicing is not included in your
warranty coverage. Additionally, your warranty
does not apply to the normal wear of items. (such
as brakes, tires, etc.)
If you believe you have a problem with your
Honda, call the service department of your
Honda dealer. Make an appointment for an
inspection and diagnosis. Remember, as the
owner of the motorcycle, you will be asked to
authorize that inspection. Your dealer will give
you the results of the inspection. If the problem is
covered under warranty, your dealer will perform
the warranty repairs for you.
If you have questions about warranty coverage
or the nature of the repair, it is best to talk to the
Service Manager of your Honda dealer.
Sometimes, in spite of the best intentions of all
concerned, a misunderstanding may occur. If you
aren’t satisfied with your dealer’s handling of the
situation, we suggest you discuss your problem
with the appropriate member of the dealership’s
management team. If the problem has already
been reviewed with the Service Manager, Parts
Manager, Sales Manager, etc., contact the Owner
of the dealership or his designated representative.
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Consumer Information 177
Contacting Honda
Your owner’s manual was written to cover
most of the questions you might ask about
your Honda. Any questions not answered in the
owner’s manual can be answered by your Honda
dealer. If he doesn’t have the answer right away,
he will get it for you.
If you have a difference of opinion with your
dealer, please remember that each dealership is
independently owned and operated. That’s why
it’s important to work to resolve any differences
at the dealership level.
If you wish to comment on your experiences with
your Honda or with your dealer, please send your
comments to the following address:
Motorcycle Division, American Honda Motor
Co., Inc., P.O. Box 2200, Torrance CA 90509-
2200, mailstop: 100-4C-7B,
telephone: (866) 784-1870.
Canada: Honda Canada Inc., Customer Relations
Dept, 180 Honda Boulevard, Markham, Ontario
L6C 0H9, telephone: (888) 946 – 6329,
facsimile: (877) 939 – 0909.
E-mail: [email protected]
Please include the following information in your
letter:
• name, address, and telephone number
• product model, year, and VIN
• date of purchase
• dealer name and address
We will likely ask your Honda dealer to respond,
or possibly acknowledge your comments directly.
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178 Consumer Information
Your Honda Dealer
Once you purchase your new Honda, get familiar
with the organization of your Honda dealer
so you can utilize the full range of services
available.
The service department is there to perform
regular maintenance and unexpected repairs. It
has the latest available service information from
Honda.
The parts department offers Honda Genuine
Parts, Pro Honda products, Honda Genuine
Accessories (USA only), and Honda accessories
and products (Canada only). The same quality
that went into your Honda can be found in
Honda Genuine replacement parts. You’ll also
find comparable quality in the accessories and
products available from the parts department.
Your Honda dealer can inform you about
competition events in your area. You’ll also find
that your dealer is a source of information (USA
only) about the Honda Rider’s Club of America.
We’re sure you’ll be as pleased with the service
your Honda dealer continues to provide after the
sale as you are with the quality and dependability
of your Honda.
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Consumer Information 179
The Honda Rider’s Club (USA only)
The Honda Rider’s Club of America (HRCA)
sponsors local riding chapters at Authorized
Honda Dealerships across the country.
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180 Index
Index
A
accessories ........................................................... 4
adjustments,
carburetor ................................................... 140
chassis ........................................................ 143
control freeplay ..........................54, 56, 60, 88
for competition........................................... 111
gearing ....................................................... 144
personal fit ................................................. 146
steering damper .......................................... 141
suspension, front ........................................ 112
suspension, rear.......................................... 126
suspension, track conditions ...................... 130
tire selection ................................................. 94
after competition maintenance .......................... 33
air cleaner .......................................................... 51
air pressure,
front suspension ......................................... 112
tires .............................................................. 93
apparel, protective ............................................... 2
appearance care ............................................... 108
authorized manuals ......................................... 174
B
basic operation .................................................. 13
before riding ........................................................ 9
between motos & practice maintenance ........... 33
brakes,
fluid level ..................................................... 89
lever, front adjustment ................................. 88
pad wear ....................................................... 91
pedal height .................................................. 88
break-in guidelines ............................................ 21
C
capacity, fuel ..................................................... 41
carburetor,
adjustment .................................................. 140
assembly .................................................... 139
circuit functions ......................................... 134
components ................................................ 134
disassembly ................................................ 137
idle speed ................................................... 140
removal ...................................................... 136
care, appearance .............................................. 108
chain drive ......................................................... 96
chassis adjustment for track conditions .......... 143
choke knob ........................................................ 15
cleaner, air ......................................................... 51
cleaning, appearance care ............................... 108
clutch system, adjustment ................................. 56
competition logbook ....................................... 167
consumer information ..................................... 173
contacting Honda ............................................ 177
controls, operating .............................................. 7
coolant ............................................................... 48
customer service ............................................. 178
cylinder system ................................................. 77
D
damping adjustments,
front ............................................................ 112
rear ............................................................. 127
dealer, your Honda .......................................... 178
diagram, wiring ............................................... 171
drive chain ......................................................... 96
E
engine,
flooded ......................................................... 16
idle speed ................................................... 140
number ....................................................... 158
oil ................................................................ 43
pinging ......................................................... 41
starting ......................................................... 15
stop button ................................................... 16
stopping ........................................................ 16
won’t start .................................................. 152
environment, protecting .................................. 151
F
filter,
air ................................................................ 51
fuel ............................................................... 42
oil ................................................................ 44
flooded engine, starting .................................... 16
fork,
front suspension adjustment ...................... 112
front suspension inspection ......................... 84
oil recommendation ..................................... 86
front brake lever adjustment ............................. 88
front suspension maintenance ........................... 84
fuel,
filter .............................................................. 42
line ............................................................... 41
oxygenated ................................................. 166
recommendation .......................................... 41
refueling ....................................................... 41
system .......................................................... 41
tank capacity ................................................ 41
valve ............................................................. 15
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Index 181
Index
(cont’d)
G
gap, spark plug .................................................. 61
gasohol ............................................................ 166
gasoline ............................................................. 41
gearing ............................................................. 144
guidelines,
steering damper .......................................... 142
suspension adjustment ............................... 131
guidelines, suspension adjustment .................. 131
H
handlebar inspection ....................................... 102
Honda,
contacting ................................................... 177
Rider’s Club ............................................... 179
service manual ........................................... 174
your dealer ................................................. 178
I
identification, vehicle ...................................... 158
idle speed, engine ............................................ 140
inspection, pre-ride ........................................... 11
L
labels, safety ........................................................ 5
logbook, competition ...................................... 167
M
maintenance,
after competition .......................................... 33
before & after competition .......................... 33
between motos & practice ........................... 33
component locations .................................... 35
general competition ..................................... 29
importance ................................................... 24
safety ............................................................ 25
schedule ........................................... 26, 27, 28
manual, service ............................................... 174
modifications ....................................................... 4
O
oil,
engine ........................................................... 43
fork ............................................................... 86
transmission ................................................. 46
operating,
controls .......................................................... 7
instructions ................................................... 13
operation component locations ........................... 8
optional,
parts list ...................................................... 169
sprockets .................................................... 169
oxygenated fuels ............................................. 166
P
pads, brake ........................................................ 91
parts, optional .................................................. 169
personal fit adjustments .................................. 146
pinging, engine .................................................. 41
plug, spark ......................................................... 61
pre-load, rear suspension ................................ 126
pre-ride inspection ............................................ 11
protective apparel ................................................ 2
R
rear suspension maintenance ............................ 85
Rider’s Club Honda ........................................ 179
riding,
apparel ............................................................ 2
basic operation ............................................. 13
before ............................................................. 9
important safety information ......................... 2
safety precautions .......................................... 2
S
safety,
a few words about ..................Safety Messages
important information .................................... 2
important precautions .................................... 2
labels .............................................................. 5
maintenance ................................................. 25
riding precautions ........................................ 14
schedule, maintenance .......................... 26, 27, 28
serial numbers ................................................. 158
service,
customer ..................................................... 178
manuals ...................................................... 174
warranty ..................................................... 176
side stand ..................................................... 14, 95
spare parts ....................................................... 170
spark arrester ..................................................... 65
spark knock ....................................................... 41
spark plug .......................................................... 61
maintenance ................................................. 61
specifications ................................................... 159
spring pre-load, rear suspension ..................... 126
starting,
engine ........................................................... 15
troubleshooting .......................................... 152
steering damper,
adjustment .................................................. 141
guidelines ................................................... 142
operation inspection ..................................... 99
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182 Index
Index
steering head bearing inspection ..................... 102
stopping engine ................................................. 16
storage ............................................................. 149
subframe ............................................................ 39
suspension,
front .............................................................. 84
rear ............................................................... 85
suspension adjustment,
for track conditions .................................... 130
front ............................................................ 112
guidelines ................................................... 131
rear ............................................................. 126
T
throttle,
freeplay ........................................................ 54
inspection ..................................................... 55
tires,
air pressure ................................................... 93
flat ................................................................ 93
selection ....................................................... 94
tools .............................................................. 169
torque specifications,
carburetor ................................................... 139
engine ......................................................... 160
frame ................................................ 161 – 163
transmission oil ................................................. 46
transporting ..................................................... 148
tripmeter ............................................................ 14
troubleshooting ............................................... 152
tubes, replacing ................................................. 93
tuning tips ....................................................... 134
V
valve clearance .................................................. 66
valve, fuel .......................................................... 15
vehicle identification no. (VIN) ...................... 158
W
warranty,
coverage ..................................................... 175
extended ..................................................... 175
washing your motorcycle ................................ 108
weight limit ......................................................... 3
wheels ............................................................... 92
wiring diagram ................................................ 171
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Record important information here:
VIN
Engine No.
Owner’s:
Name
Address
City/State
Phone
Dealer’s:
Name
Address
City/State
Phone
Service Mgr.
Maintenance The maintenance schedule (pages 27-28) lists service frequencies for:
about 2.5 hours,
about 7.5 hours,
about 15.0 hours,
about 22.5 hours, and about every 30.0 hours.
Pre-ride Inspection Check the items listed on the Pre-ride inspection checklist each time before you ride
(page 11):
Fuel/Capacity unleaded gasoline, pump octane number of 91 or higher
tank: 1.90 US gal (7.2 ℓ), reserve: 0.42 US gal (1.6 ℓ)
Engine oil Pro Honda GN4 4-stroke oil (USA & Canada), or Honda 4-stroke oil, or an equivalent
motorcycle oil.
Transmission oil Pro Honda GN4 4-stroke oil (USA & Canada), or Honda 4-stroke oil, or an equivalent
motorcycle oil.
Tires Front 80/100-21 51M Rear 110/100-18 64M
DUNLOP D742FA DUNLOP D756
Type bias-ply, tube type
Tire Pressure
(cold)
Front: 15 psi (100 kPa, 1.0 kgf/cm
2
)
Rear: 15 psi (100 kPa, 1.0 kgf/cm
2
)
Spark Plug standard: IFR8H11 (NGK) or VK24PRZ11 (DENSO)
optional: IFR9H11 (NGK) or VK27PRZ11 (DENSO)
Coolant ethylene glycol antifreeze (silicate-free) for aluminum engines in 50/50 solution with Pro
Honda HP Coolant or an equivalent distilled water
Fuse main: 15 A
Drive Chain
Size/Link
DID 520MXV/114
Quick Reference
The following is a brief, but important collection
of information you need to know about your
Honda. You’ll also find space to record important
notes.
How To Avoid Costly Repairs
The engine of your Honda can be the most
expensive component to repair. Proper
maintenance, especially the use of the
recommended fluids and filters, prevents
premature wear and damage.
Frequent causes of costly engine repairs are:
• Transmission oil & engine oil — insufficient
quantity, improper oil.
• Air cleaner — dirty, leaking because of
improper installation (poor seal).
Quick Reference
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