engine YAMAHA GRIZZLY 450 2009 Workshop Manual

8-34
8 11. Insert the air filter element into the air filter
case, and then install the air filter case cover
by hooking the holders onto the air filter case.
12. Install the seat.
TIPThe air filter element should be cleaned every 20–
40 hours. It should be cleaned and lubricated more
often if the ATV is operated in extremely dusty ar-
eas. Each time the air filter element maintenance
is performed, check the air inlet of the air filter case
for obstructions. Check the air filter case rubber
joint to the carburetor fittings and the rubber joint
manifold fittings for an air-tight seal. Tighten all fit-
tings securely to avoid the possibility of unfilteredair entering the engine.NOTICEECB00460
Make sure that the air filter element is prop-
erly seated in the air filter case.
Never operate the engine with the air filter el-
ement removed. This will allow unfiltered air
to enter the engine, causing rapid engine
wear and possible engine damage. Addition-
ally, operation without the air filter elementwill affect carburetor jetting with subsequent
poor performance and possible engine over-
heating.EBU27081Cleaning the spark arrester Be sure the exhaust pipe and muffler are cool be-
fore cleaning the spark arrester.
1. Remove the bolts.
2. Remove the tailpipe by pulling it out of the
muffler.1. Bolt
2. Tailpipe
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8-35
83. Tap the tailpipe lightly, and then use a wire
brush to remove any carbon deposits from the
spark arrester portion of the tailpipe and inside
of the tailpipe housing.
4. Insert the tailpipe into the muffler and align the
bolt holes.
5. Install the bolts and tighten them to the speci-
fied torque.
WARNING
EWB02340Do not start the engine when cleaning the
spark arrester, otherwise it could cause injury
to the eyes, burns, carbon monoxide poison-
ing, possibly leading to death, and start a fire.
Always let the exhaust system cool prior totouching exhaust components.EBU23920V-belt cooling duct check hose If dust or water collects in the V-belt cooling duct
check hose, remove the hose and clean it.
1. Tailpipe
2. Spark arresterTightening torque:
Tailpipe bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
1. V-belt cooling duct check hose (left front side of ATV)
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8
EBU23930V-belt case drain plug After riding in water deep enough to allow it to en-
ter the V-belt case, remove this plug to drain the
water from the case.TIPIf water drains from the V-belt case after removing
the plug, have a Yamaha dealer check the ATV asthe water may affect other engine parts.
EBU23940Adjusting the carburetor The carburetor should be checked and, if neces-
sary, adjusted at the intervals specified in the peri-
odic maintenance and lubrication chart. The
carburetor is an important part of the engine and
requires very sophisticated adjustment. Therefore,
most carburetor adjustments should be left to a
Yamaha dealer, who has the necessary profes-
sional knowledge and experience. The adjustment
described in the following section, however, may
be performed by the owner as part of routine main-
tenance.NOTICEECB00480The carburetor has been set and extensively
tested at the Yamaha factory. Changing these
settings without sufficient technical knowl-
edge may result in poor performance of ordamage to the engine.EBU24010Adjusting the engine idling speed The engine idling speed must be checked and, if
necessary, adjusted as follows at the intervals
specified in the periodic maintenance and lubrica-
tion chart.
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8
TIPA diagnostic tachometer is needed to make thisadjustment.
1. Start the engine and warm it up.TIPThe engine is warm when it quickly responds to thethrottle.
2. Remove panel D. (See page 8-9.)
3. Attach the tachometer to the spark plug lead.
4. Check the engine idling speed and, if neces-
sary, adjust it to specification by turning the
throttle stop screw at the carburetor. To in-
crease the engine idling speed, turn the throt-
tle stop screw in direction (a), and to decrease
it, turn the screw in direction (b).
TIPIf the specified idling speed cannot be obtained as
described above, have a Yamaha dealer make theadjustment.
5. Install the panel.1. Throttle stop screwEngine idling speed:
1450–1550 r/min
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8
EBU24045Adjusting the throttle cable free play The throttle cable free play should be checked
and, if necessary, adjusted at the intervals speci-
fied in the periodic maintenance and lubrication
chart.
The throttle cable free play should measure 3.0–
5.0 mm (0.12–0.20 in) at the throttle lever. Period-
ically check the throttle cable free play and, if nec-
essary, adjust it as follows.TIPThe engine idling speed must be checked, and ad-
justed if necessary, before adjusting the throttle ca-ble free play.
1. Slide the rubber cover back.
2. Loosen the locknut.
3. To increase the throttle cable free play, turn
the throttle cable free play adjusting bolt in di-
rection (a). To decrease the throttle cable free
play, turn the adjusting bolt in direction (b).4. Tighten the locknut.
5. Slide the rubber cover to its original position.
EBU24060Valve clearance The valve clearance changes with use, resulting in
improper air-fuel mixture and/or engine noise. To
prevent this from occurring, the valve clearance
must be adjusted by a Yamaha dealer at the inter-
vals specified in the periodic maintenance and lu-
brication chart.1. Rubber cover
2. Throttle cable free play adjusting bolt
3. Locknut
4. Throttle cable free play
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8
EBU24900Checking and lubricating the cables The operation and the condition of all control ca-
bles should be checked before each ride, and the
cables and cable ends should be lubricated if nec-
essary. If a cable is damaged or does not move
smoothly, have a Yamaha dealer check or replace
it.
WARNING
EWB02130Inspect cables frequently and replace if dam-
aged. Corrosion can result when the cable
sheaths become damaged, and cables can
also become frayed or kinked, which could re-
strict the operation of controls and lead to anaccident or injury.EBU28711Checking and lubricating the front and
rear brake levers The operation of the front and rear brake levers
should be checked before each ride, and the lever
pivots should be lubricated if necessary.
EBU28832Checking and lubricating the brake
pedal The operation of the brake pedal should be
checked before each ride, and the pedal pivot
should be lubricated if necessary. Recommended lubricant:
Engine oilRecommended lubricants:
Front brake lever:
Silicone grease
Rear brake lever:
Lithium-soap-based grease
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8
EBU25782Troubleshooting charts Starting problems or poor engine performance
Check the fuel level in
the fuel tank.1. Fuel
There is enough fuel.
There is no fuel.
Check the compression.
Supply fuel.
The engine does not start.
Check the compression.
Operate the electric starter.2. Compression
There is compression.
There is no compression.
Check the ignition.
Have a Yamaha dealer
check the ATV.
Remove the spark plug
and check the electrodes.3. Ignition
Wipe off with a dry cloth and correct the
spark plug gap, or replace the spark plug.
Have a Yamaha dealer check the ATV.
The engine does not start.
Have a Yamaha dealer
check the ATV.
The engine does not start.
Check the battery.
Operate the electric starter.4. Battery
The engine turns over
quickly.
The engine turns over
slowly.
The battery is good.Check the battery lead connections,
and charge the battery if necessary.
DryWet
Open the throttle halfway and operate
the electric starter.
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8 Engine overheating
WARNING
EWB02290Wait 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.TIPIf coolant is not available, tap water can be temporarily used instead, provided that it is changed to the rec-ommended coolant as soon as possible.Wait until the
engine has cooled.
Check the coolant level in the
reservoir and radiator.
The coolant level
is OK.The coolant level is low.
Check the cooling system
for leakage.
Have a Yamaha dealer check
and repair the cooling system.Add coolant. (See TIP.)
Start the engine. If the engine overheats again, have a
Yamaha dealer check and repair the cooling system.
There is
leakage.
There is
no leakage.
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9
EBU25860
CLEANING AND STORAGE
EBU25880Cleaning Frequent, thorough cleaning of your ATV will not
only enhance its appearance but will improve its
general performance and extend the useful life of
many components.
1. Before cleaning the ATV:
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 plug and all filler caps
are properly installed.
2. If the engine case is excessively greasy, apply
degreaser with a paint brush. Do not apply de-
greaser to the wheel axles.
3. Rinse the dirt and degreaser off with a garden
hose. Use only enough pressure to do the job.NOTICEECB00710Excessive water pressure may cause water
seepage and deterioration of wheel bearings,
brakes, transmission seals and electrical de-
vices. Many expensive repair bills have result-ed from improper high-pressure detergent
applications such as those available in coin-
operated car washers.
4. Once most of the dirt has been hosed off,
wash all surfaces with warm water and mild,
detergent-type soap. An old toothbrush or bot-
tle brush is handy for hard-to-reach places.
5. Rinse the ATV off immediately with clean wa-
ter and dry all surfaces with a chamois, clean
towel or soft absorbing cloth.
6. Clean the seat with a vinyl upholstery cleaner
to keep the cover pliable and glossy.
7. Automotive type wax may be applied to all
painted and chrome plated surfaces. Avoid
combination cleaner-waxes. Many contain
abrasives which may mar the paint or protec-
tive finish. When finished cleaning, start the
engine and let it idle for several minutes.
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9
WARNING
EWB02310Wet brakes may have reduced stopping ability,
increasing the chance of an accident. Test the
brakes after washing. Apply the brakes several
times at slow speeds to let friction dry out thelinings.EBU25932Storage Short-term
Always store your ATV in a cool, dry place and, if
necessary, protect it against dust with a porous
cover.NOTICEECB00720
Storing the ATV in a poorly ventilated room
or covering it with a tarp while it is still wet,
will allow water and humidity to seep in and
cause rust.
To prevent corrosion, avoid damp cellars,
stables (because of the presence of ammo-
nia) and areas where strong chemicals arestored.Long-term
Before storing your ATV for several months:
1. Follow all the instructions in the “Cleaning”
section of this chapter.
2. Turn the fuel cock lever to “OFF”.
3. Drain the carburetor float chamber by loosen-
ing the drain bolt; this will prevent fuel deposits
from building up. Pour the drained fuel into the
fuel tank.
4. Fill up the fuel tank and add fuel stabilizer (if
available) to prevent the fuel from deteriorat-
ing.
5. Perform the following steps to protect the cyl-
inder, piston rings, etc. from corrosion.
a. Remove the spark plug cap and spark
plug.
b. Pour a teaspoonful of engine oil into the
spark plug bore. Specified amount:
7.5 ml of stabilizer to each liter of fuel (or 1 oz
of stabilizer to each gallon of fuel)
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