2008 YAMAHA WOLVERINE 450 check engine

8-36
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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8-37
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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8-38
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

8-45
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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8-56
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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8-57
8Engine 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.NOTE:If 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 NOTE.)
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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9-3
9 c. Install the spark plug cap onto the spark
plug, and then place the spark plug on the
cylinder head so that the electrodes are
grounded. (This will limit sparking during
the next step.)
d. Turn the engine over several times with the
starter. (This will coat the cylinder wall with
oil.)
e. Remove the spark plug cap from the spark
plug, and then install the spark plug and
the spark plug cap.
6. Lubricate all control cables and the pivoting
points of all levers and pedals.
7. Check and, if necessary, correct the tire air
pressure, and then block up the ATV so that
all of its wheels are off the ground. Alternative-
ly, turn the wheels a little every month in order
to prevent the tires from becoming degraded
in one spot.
8. Cover the muffler outlet with a plastic bag to
prevent moisture from entering it.
9. Remove the battery and fully charge it. Store
it in a cool, dry place and charge it once a
month. Do not store the battery in an exces-
sively cold or warm place [less than 0 °C (30°F) or more than 30 °C (90 °F)]. For more in-
formation on storing the battery, see page
8-47.
NOTE:Make any necessary repairs before storing theATV.
U3C262E0.book Page 3 Tuesday, June 26, 2007 3:36 PM

INDEX
AAccessories and loading ................................................ 6-6
Air filter element, cleaning ............................................ 8-31
Axle boots .................................................................... 8-44BBattery .......................................................................... 8-47
Brake fluid, changing .................................................... 8-41
Brake fluid level, checking ............................................ 8-39
Brake lever free play and brake pedal position (rear),
adjusting and checking .............................................. 8-42
Brake lever free play, checking the front ...................... 8-41
Brake lever, front ............................................................ 4-8
Brake levers, checking and lubricating ......................... 8-45
Brake light switches ..................................................... 8-44
Brake pads, checking the front and rear ...................... 8-38
Brake pedal and rear brake lever ................................... 4-8
Brake pedal, checking and lubricating ......................... 8-46
Brakes, front and rear .................................................... 5-4CCables, checking and lubricating ................................. 8-45
Carburetor, adjusting .................................................... 8-36
Chassis fasteners ........................................................... 5-7
Cleaning ......................................................................... 9-1
Coolant .................................................................. 5-3, 8-26
Coolant temperature warning light ................................. 4-2
Cowlings and panels, removing and installing ............... 8-9DDifferential gear oil ......................................................... 5-3Differential gear oil, changing ....................................... 8-24
Drive select lever ............................................................ 4-9
Drive select lever and driving in reverse ........................ 6-3
Drive select lever safety system cable, adjusting ......... 8-38
EEngine break-in .............................................................. 6-5
Engine, cold start ........................................................... 6-1
Engine idling speed ...................................................... 8-36
Engine oil ....................................................................... 5-3
Engine oil and oil filter cartridge ................................... 8-17
Engine, starting a warm ................................................. 6-3
Engine stop switch ......................................................... 4-4FFinal gear oil .......................................................... 5-3, 8-22
Four-wheel-drive indicator .............................................. 4-3
Fuel ......................................................................... 4-9, 5-3
Fuel cock ...................................................................... 4-10
Fuel tank cap .................................................................. 4-9
Fuses, replacing ........................................................... 8-48HHandlebar switches ........................................................ 4-4
Headlight beam, adjusting ............................................ 8-52
Headlight bulb, replacing .............................................. 8-50IIdentification numbers .................................................. 11-1
Indicator lights and warning light .................................... 4-2
Instruments, lights and switches .................................... 5-7
U3C262E0.book Page 1 Tuesday, June 26, 2007 3:36 PM