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EBU00302
Idle speed adjustment
NOTE:
A diagnostic tachometer must be used for this
procedure.
NOTE:
The throttle cables and carburetor synchroniza-
tion must be set properly before adjusting the
idle speed.
1. Adjust the pilot air screws.
8Turn in both pilot air screws until they
lightly seat.
8Turn out both pilot air screws to specifi-
cation. (Refer to the “Carburetor settings”
section.)
2. Remove the seat.
3. Start the engine and warm it up for a few
minutes at approximately 1,000 to 2,000
r/min.
q
1. Pilot air screw1. Vis d’air de ralenti1. Tornillo de aire piloto
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8-69
4. Connect the tachometer and set the idle to
the specified idling speed by turning the
idle adjust screws.
cC
8Idle speed adjust screws were preset at
the factory. When adjusting idle speed,
turn the right and left idle speed adjust
screws the same amount, or carburetor
synchronization will be incorrect.
8The pilot air screws and idle speed adjust
screws are separate adjustments but they
must be adjusted at the same time to
achieve optimum engine performance.
q
1. Idle speed adjust screw1. Vis de réglage du régime de ralenti1. Tornillo de ajuste de la velocidad de ralentí
Specified idle speed:
1,450–1,550 r/min
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EBU00307
Throttle lever adjustment
NOTE:
Adjust the engine idling speed before adjusting
the throttle lever free play.
1. Loosen the locknut.
2. Turn the adjusting bolt until the throttle
lever free play is 4–6 mm.
3. Tighten the locknut.
qw
a
1. Adjusting bolt 2. Locknut a. Free play1. Boulon de réglage 2. Contre-écrou a. Jeu1. Perno de ajuste 2. Contratuerca a. Juego libre
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8-97
3. Thoroughly lubricate the drive chain with a
special O-ring chain lubricant.
cC
Do not use engine oil or any other lubricants
for the drive chain, as they may contain sub-
stances that could damage the O-rings.
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EBU00570
Cable inspection and lubrication
w
Inspect cables frequently and replace if dam-
aged. Corrosion can result when the outer
covering of control cables becomes dam-
aged. Cables can also become frayed or
kinked. Operation of controls could be
restricted, which could cause an accident or
injury.
Lubricate the inner cables and the cable ends. If
the cables do not operate smoothly, ask a
Yamaha dealer to replace them.
Recommended lubricant:
Engine oil
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EBU00440
Troubleshooting chart
Starting problems or poor engine performance
Check fuel flow
1. Fuel
Check if there is
fuel in the fuel
tank
2. Compression
Kick the kick starter
to see if there is
compression
3. Ignition
Remove plugs and
check electrodes
WetWipe clean with
dry cloth
DryAttach plug cap and
ground to chassisKick the kick
starter stronglySpark weak
Spark goodIgnition system normal
No spark
Ask a Yamaha dealer to inspect
Adjust plug gap or
replace plug(s)
There is compressonCompression normal
Ask a Yamaha dealer to inspectNo compression
There is fuelTurn the fuel
cock to “OFF”
Remove the
fuel pipeNo fuelFuel cock clogged
Some fuelTurn the fuel
cock to “RES”Restart engine
No fuelSupply fuel
Clean fuel cock
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Engine overheating
Wait until the
engine has cooled.Check the coolant level in the
reservoir tank and/or radiator.
Level is OK.
Level is low, check the
cooling system for leakage.
No
leakage.
Leakage.Ask a Yamaha dealer
to inspect and repair
the cooling system.
Add coolant.
(See NOTE.)
Restart the engine. If the engine overheats
again, ask a Yamaha dealer to inspect and
repair the cooling system.
NOTE:
If it is difficult to get recommended coolant, tap water can be temporarily used, provided that it is
changed to the recommended coolant as soon as possible.
w
Wait for the engine and radiator to cool before removing the radiator cap. You could be burned
by hot fluid and steam blown out under pressure. Always put a thick rag over the cap when
opening. Allow any remaining pressure to escape before completely removing the cap.
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EBU00416
CLEANING AND STORAGE
A. CLEANING
Frequent, thorough cleaning of your machine
will not only enhance its appearance but will
improve its general performance and extend the
useful life of many components.
1. Before cleaning the machine:
a. Block off the end of the exhaust pipe to
prevent water entry. A plastic bag and
strong rubber band may be used.
b. Make sure the spark plugs and all filler
caps are properly installed.
2. If the engine case is excessively greasy,
apply degreaser with a paint brush. Do not
apply degreaser to the chain, sprockets or
wheel axles.
3. Rinse the dirt and degreaser off with a gar-
den hose. Use only enough pressure to do
the job.
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