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SERVICE AND ADJUSTMENTS
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Carburetor adjustment is critical and if done improperly adjustment should be no morethan the widthoftheslot in the
can permanently damage the engine as well as the car- adjusting screw.
buretor. Please read all instructions and consult the • Turn bothof the mixture screws counterclockwiseuntflthey
Troubleshooting section of this manual before begin- stop.Do notattemptto adjustthe screwbeyondthe stopsas
ning this process, if the engine does not operate accord- damagecan occur.
ing to these instructions after repeating the adjusting • Turntheidlespeedscrewclockwise1/2 turn.
steps, do not use the unit, For further assistance, please • Starttheengineandoperateforthree )3) minutestowarmup.
call our customer assistance hotline at 1-800-235-5878. Goto"Adjusting procedure?
WARNING:
MAKE CARBURETOR ADJUSTMENTS
WITH THE LOWER END SUPPORTED TO
PREVENT BLADE FROM CONTACTING
ANY OBJECT. HOLD UNIT WITH YOUR
HAND.
THE BLADE WILL BE MOVING DURING
MOST OF THIS PROCEDURE, WEAR
YOUR PROTECTIVE EQUIPMENT AND
OBSERVE ALL SAFETY PRECAUTIONS.
IN "LOW SPEED MIXTURE ADJUST-
MENT," RECHECK IDLE SPEED AFTER
EACH ADJUSTMENT. THE CUTTING
BLADE MUST NOT MOVE AT IDLE SPEED.
If enginedoes not start, it may be flooded,tf in doubt, read the
sectiononflooded engine inthe starting section of this manual
priorto beginning any adjustments.
If you are unsure about adjusting the carburetor or experience
any problemwhile attemptingthisprocess, please cal!the 1-800
number listed on the front cover of this manualfor further assis-
tance.
The carburetor has been adjusted at the factory for sea level
conditions. Adjustments may become necessary if the unit is
used at significantly higher altitudesor if you notice any of the
following conditions:
• Enginewillnot continue to run at idle position.See =Idlespeed
adjustment."
• Blade continues to move when the engine idles.See "Idle
speed adjustment."
• Engine dies or hesitates when it should accelerate. See
"Acceleration check?"
° Loss of cuttingpow,er which cannot be corrected by cleaning
the air filter.See High speed adjustment."
NOTE.-Donot attemptto turn the adjustmentsbeyond the stops
as damage can occur.
CARBURETOR PRESETS (Fig. 16)
The carburetorhasthree adjustingscrews:
L= Low speedmixture adjusting screw
H = Highspeedmixture adjustingscrew
T = Idlespeed adjusl_ngscrew
Ifyour enginewillnotstart due to suspectedimpropercarbure-
toradjustment, the following presets may be required. Ifused, it
is recommended that all steps w;thin the adjustment procedure
be completed inorder at assure a properly set carburetor If pre-
sets are not needed, proceedto section=Idlespeed adjustment."
Very small adjustments can affect engineperformance. It is
important to tum the screw a very small amount per adjustment
and test performance before making further adjustments. Each
ADJUSTING PROCEDURE
IDLE SPEED ADJUSTMENT
Allowthe warmenginetoidle.
Adjustthe idlespeedscrewuntilthe enginecontinuesto run
withoutstallingandwithoutthe bladeturning.
- Turnscrewclockwisetoincreaseengine speedif enginestalls
or dies.
- Turnscrew counterclockwiseto stow engine down and/or to
keepthe bladefrom turning.
• No further adjustmentsare necessary if blade does not move
at idlespeed and if performance issatisfactory.
LOW SPEED ..._,
MIXTURE
ADJUSTMENT
IDLE SPEED
HIGH SPEED
MIXTURE
COVER
Figure 16
LOW SPEED MIXTURE ADJUSTMENT
• Allowenginetoidle.
• Turnthelowspeedmixtureadjustment slowlyclockwiseuntil
the RPM startstodrop.Note theposition.
• Turnthe low speedadjustmentslowlycounterclockwiseuntil
the RPMspeedsupand startstodropagain.Notetheposition.
• Set the lowspeedmixturescrewat the midpoint betweenthe
twopositions.
HIGH SPEED MIXTURE ADJUSTMENT
IMPORTANT:DONOTOPERATEENGINE ATFULLTHROTTLE
FOR PROLONGEDPERIODS WHILE MAKING HIGH SPEED
ADJUSTMENTSAS DAMAGETOTHE ENGINE CAN OCCUR.
• Makea test cuL
• Based on performanceof the unitwhile cutting,adjust the
highspeed mixtureadjustmentin 1/16 turn incrementsas fol-
lows:
- Clockwiseif unitsmokes orlosespower whilecutting.Do not
adjustfor bestpower by sound or speed, but judge by how
welltheunitperformsduringoperation.
- Counterclockwiseif the unithas speed while not cutting,but
diesor lackspower whilecuring.
• Repeatthe test cut.
• Continue w_ 1/16 turn adjustments until the unit perfor-
mance is acceptablewhilecutting.
• After completing adjustments, checkfor aoceleralJon.
• If unit accelerates properly no further adjustments are neces-
sary.Ifnot, proceedto accelerationcheck.
ACCELERATION CHECK
• fftheenginedies orhesitatesinsteadofaccelerating,turnthe
lowspeed mixture adjustment1/16 of a turnat a timecoun-
terclockwiseuntilyouhavesmooth acceleration.
• Checkthe idle speedforstability and thatthe bladedoes not
turn.Adjustas necessary.
• Recheckfor smoothacceleration and stable idle,
• Repeat process as necessary for acceptable performance.
-16-
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