2008 YAMAHA WOLVERINE 450 engine

8-17
82. Clean the surface of the spark plug gasket
and its mating surface, and then wipe off any
grime from the spark plug threads.
3. Install the spark plug with the spark plug
wrench, and then tighten it to the specified
torque.
NOTE:If a torque wrench is not available when installing
a spark plug, a good estimate of the correct torque
is 1/4–1/2 turn past finger tight. However, the spark
plug should be tightened to the specified torque assoon as possible.
4. Install the spark plug cap.EBU26425Engine oil and oil filter cartridge The engine oil level should be checked before
each ride. In addition, the oil must be changed and
the oil filter cartridge replaced at the intervals spec-
ified in the periodic maintenance and lubrication
chart.
To check the engine oil level
1. Place the ATV on a level surface.
2. Remove panel D. (See page 8-9.)
3. Check the engine oil level on a cold engine.NOTE:If the engine was started before checking the oil
level, be sure to warm up the engine sufficiently,
and then wait at least ten minutes until the oil set-tles for an accurate reading.
1. Spark plug gapTightening torque:
Spark plug:
17.5 Nm (1.75 m·kgf, 12.7 ft·lbf)
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8-18
8 4. Remove the engine oil filler cap, and then
wipe the dipstick off with a clean rag.
5. Insert the dipstick into the filler hole (without
screwing it in), and then remove it again to
check the oil level.
NOTE:The engine oil should be between the minimumand maximum level marks.
6. If the engine oil is at or below the minimum
level mark, add sufficient oil of the recom-
mended type to raise it to the correct level.
7. Insert the dipstick into the oil filler hole, and
then tighten the engine oil filler cap.
8. Install the panel.
1. Engine oil filler cap
1. Dipstick
2. Maximum level mark
3. Minimum level mark
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8-19
8To change the engine oil (with or without oil fil-
ter cartridge replacement)
1. Place the ATV on a level surface.
2. Remove panel D. (See page 8-9.)
3. Start the engine, warm it up for several min-
utes, and then turn it off.
4. Place an oil pan under the engine to collect
the used oil.
5. Remove the engine oil filler cap, and then re-
move the engine oil drain bolt to drain the oil
from the crankcase.
NOTE:Skip steps 6–10 if the oil filter cartridge is not beingreplaced.
6. Remove panel C. (See page 8-9.)
7. Remove the oil filter cartridge with an oil filter
wrench.
1. Engine oil drain bolt
1. Oil filter cartridge
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8-20
8
NOTE:An oil filter wrench is available at a nearby Yamahadealer.
8. Apply a thin coat of engine oil to the O-ring of
the new oil filter cartridge.
NOTE:Make sure that the O-ring is properly seated.
9. Install the new oil filter cartridge with an oil fil-
ter wrench, and then tighten it to the specified
torque with a torque wrench.
1. Oil filter wrench
1. O-ring
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8-21
8
10. Install panel C.
11. Install the engine oil drain bolt, and then tight-
en it to the specified torque.12. Add the specified amount of the recommend-
ed engine oil, and then install and tighten the
engine oil filler cap.
NOTE:Be sure to wipe off spilled oil on any parts after theengine and exhaust system have cooled down.CAUTION:ECB00300
In order to prevent clutch slippage (since the
engine oil also lubricates the clutch), do not
mix any chemical additives. Do not use oils
with a diesel specification of “CD” or oils of
a higher quality than specified. In addition,
do not use oils labeled “ENERGY CONSERV-
ING II” or higher.
1. Torque wrenchTightening torque:
Oil filter cartridge:
17 Nm (1.7 m·kgf, 12 ft·lbf)
Tightening torque:
Engine oil drain bolt:
23 Nm (2.3 m·kgf, 17 ft·lbf)
Recommended oil:
See page 10-1.
Oil quantity:
Without oil filter cartridge replacement:
2.30 L (2.43 US qt) (2.02 Imp.qt)
With oil filter cartridge replacement:
2.40 L (2.54 US qt) (2.11 Imp.qt)
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8-22
8

Make sure that no foreign material enters thecrankcase.
13. Start the engine, and then let it idle for several
minutes while checking it for oil leakage. If oil
is leaking, immediately turn the engine off and
check for the cause.
14. Turn the engine off, wait at least ten minutes,
and then check the oil level and correct it if
necessary.
15. Install panel D.EBU23381Final gear oil The final gear case must be checked for oil leak-
age before each ride. If any leakage is found, have
a Yamaha dealer check and repair the ATV. In ad-
dition, the final gear oil level must be checked and
the oil changed as follows at the intervals specified
in the periodic maintenance and lubrication chart.
To check the final gear oil level
1. Place the ATV on a level surface.NOTE:The final gear oil level must be checked on a coldengine.2. Remove the final gear oil filler bolt, and then
check the oil level in the final gear case.
NOTE:The oil level should be at the brim of the filler hole.
3. If the oil is below the brim of the filler hole, add
sufficient oil of the recommended type to raise
it to the correct level.
4. Install the oil filler bolt, and then tighten it to the
specified torque.1. Final gear oil
2. Final gear oil filler bolt
3. Correct oil level
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8-26
8

The differential gear case capacity is greater
than the recommended oil quantity, therefore
the oil level cannot be accurately checked fromthe oil filler hole.CAUTION:ECB00410Be sure no foreign material enters the differen-tial gear case.
6. Install the oil filler bolt, and then tighten it to the
specified torque.
7. Check the differential gear case for oil leak-
age. If oil is leaking, check for the cause.
EBU23470Coolant The coolant level should be checked before each
ride. In addition, the coolant must be changed at
the intervals specified in the periodic maintenance
and lubrication chart.EBU27940To check the coolant level
1. Place the ATV on a level surface.NOTE:The coolant level must be checked on a cold en-
gine since the level varies with engine tempera-ture.
2. Check the coolant level in the coolant reser-
voir.NOTE:The coolant should be between the minimum andmaximum level marks. Recommended differential gear oil:
See page 10-1.
Oil quantity:
0.35 L (0.37 US qt) (0.31 Imp.qt)
Tightening torque:
Differential gear oil filler bolt:
23 Nm (2.3 m·kgf, 17 ft·lbf)
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8-28
8

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.
NOTE:
The radiator fan is automatically switched on or
off according to the coolant temperature in the
radiator.
If the engine overheats, see page 8-56 for fur-ther instructions.EBU26441To change the coolant
WARNING
EWB01890Wait 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 place a thick rag over the cap
when opening. Allow any remaining pressureto escape before completely removing the cap.
1. Place the ATV on a level surface.
2. Remove panels C and D. (See page 8-9.)3. Place a container under the engine, and then
remove the coolant drain bolt. (Use a trough
or a similar object as shown to prevent coolant
from spilling on the footrest.)
1. Coolant drain bolt
U3C262E0.book Page 28 Tuesday, June 26, 2007 3:36 PM