engine YAMAHA WOLVERINE 450 2008 Service Manual

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8 10. Connect the coolant reservoir hose.
11. Pour the recommended coolant into the reser-
voir to the maximum level mark, and then in-
stall the reservoir cap.
12. Pour the recommended coolant into the radia-
tor until it is full.
CAUTION:ECB00401
If coolant is not available, use distilled water
or soft tap water instead. Do not use hard wa-
ter or salt water since it is harmful to the en-
gine.

If water has been used instead of coolant, re-
place it with coolant as soon as possible,
otherwise the cooling system will not be pro-
tected against frost and corrosion.
If water has been added to the coolant, have
a Yamaha dealer check the antifreeze con-
tent of the coolant as soon as possible, oth-
erwise the effectiveness of the coolant willbe reduced.
13. Install the radiator cap, start the engine, let it
idle for several minutes, and then turn it off.
14. Remove the radiator cap to check the coolant
level in the radiator. If it is low, add sufficient
coolant until it reaches the top of the radiator,
and then install the radiator cap.
15. Start the engine, and then check for coolant
leakage.
NOTE:If any leakage is found, have a Yamaha dealercheck the cooling system.
16. Install the cowling.
17. Install the panels. Antifreeze/water mixture ratio:
1:1
Recommended antifreeze:
High-quality ethylene glycol antifreeze con-
taining corrosion inhibitors for aluminum en-
gines
Coolant quantity:
Radiator capacity (including all routes):
1.32 L (1.40 US qt) (1.16 Imp.qt)
Coolant reservoir capacity (up to the maxi-
mum level mark):
0.25 L (0.26 US qt) (0.22 Imp.qt)
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8-32
8 4. Pull off the lock plate, and then remove the
sponge material from the air filter element
frame.5. Wash the sponge material gently but thor-
oughly in solvent.
WARNING
EWB01940Always use parts cleaning solvent to clean the
sponge material. Never use low-flash-point
solvents or gasoline to clean the sponge mate-
rial because the engine could catch fire or ex-plode.
6. Squeeze the excess solvent out of the sponge
material and let it dry.
1. Air filter element
1. Air filter element frame
2. Sponge material
3. Air filter element lock plate
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8
CAUTION:ECB00440Do not twist the sponge material when squeez-ing it.
7. Check the sponge material and replace it if
damaged.
8. Apply a quality foam air filter oil to the sponge
material.NOTE:The sponge material should be wet but not drip-ping.
9. Pull the sponge material over the air filter ele-
ment frame, and then install the lock plate.10. 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.
11. Install the seat.
NOTE:The 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.CAUTION:ECB00460
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 element
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8 will affect carburetor jetting with subsequent
poor performance and possible engine over-
heating.EBU27011Cleaning the spark arrester Be sure the exhaust pipe and muffler are cool be-
fore cleaning the spark arrester.
1. Remove the tailpipe cover by removing the
bolts.
2. Remove the tailpipe by pulling it out of the
muffler.3. 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 tailpipe cover by installing the bolts,
and then tighten them to the specified torque.1. Bolt
2. Tailpipe cover
1. Tailpipe
2. Spark arresterTightening torque:
Tailpipe bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
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8
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.
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.NOTE:If 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.
1. V-belt cooling duct check hose (left front side of ATV)
1. V-belt case drain plug
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8
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.CAUTION:ECB00480The 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.EBU24000Adjusting 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.
NOTE:A diagnostic tachometer is needed to make thisadjustment.
1. Start the engine and warm it up.NOTE:The engine is warm when it quickly responds to thethrottle.
2. Attach the tachometer to the spark plug lead.
3. 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).
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8
NOTE:If the specified idling speed cannot be obtained as
described above, have a Yamaha dealer make theadjustment.
EBU24043Adjusting 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.NOTE:The engine idling speed must be checked, and ad-
justed if necessary, before adjusting the throttle ca-ble free play.
1. Loosen the locknut.
2. To increase the throttle cable free play, turn
the adjusting bolt in direction (a). To decrease
the throttle cable free play, turn the adjusting
bolt in direction (b).
1. Throttle stop screwEngine idling speed:
1450–1550 r/min
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8 3. Tighten the locknut.
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.
EBU24070Adjusting the drive select lever safety
system cable The drive select lever safety system cable stretch-
es with use, which can result in improper function.
Therefore, the safety system cable should be
checked and adjusted at the intervals specified in
the periodic maintenance and lubrication chart.EBU24130Checking the front and rear brake pads The front and rear brake pads must be checked for
wear at the intervals specified in the periodic main-
tenance and lubrication chart.EBU24171Front brake pads
Check each front brake pad for damage and mea-
sure the lining thickness. If a brake pad is dam-
aged or if the lining thickness is less than 1.0 mm
(0.04 in), have a Yamaha dealer replace the brake
pads as a set.
1. Locknut
2. Throttle cable free play adjusting bolt
3. Throttle cable free playU3C262E0.book Page 38 Tuesday, June 26, 2007 3:36 PM

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83. Install the panel.
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.EBU28710Checking 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.
1. Brake light switch
2. Brake light switch adjusting nutRecommended lubricant:
Engine oil
Recommended lubricants:
Front brake lever:
Silicone grease
Rear brake lever:
Lithium-soap-based grease (all-purpose
grease)
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8
EBU25781Troubleshooting 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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