2008 YAMAHA WOLVERINE 350 Owners Manual

8-10
8 To install the spark plug
1. Measure the spark plug gap with a wire thick-
ness gauge and, if necessary, adjust the gap
to specification.
2. 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.EBU23313Engine 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. Specified spark plug:
NGK/DR8EA
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)
1. Spark plug gap
Tightening torque:
Spark plug:
17.5 Nm (1.75 m·kgf, 12.7 ft·lbf)
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8-11
82. 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.
3. Remove the engine oil filler cap, and then
wipe the dipstick off with a clean rag.
4. 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.
5. 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.
6. Insert the dipstick into the oil filler hole, and
then tighten the engine oil filler cap.
1. Engine oil filler cap
1. Dipstick
2. Maximum level mark
3. Minimum level mark
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8-12
8 To change the engine oil (with or without oil fil-
ter cartridge replacement)
1. Place the ATV on a level surface.
2. Start the engine, warm it up for several min-
utes, and then turn it off.
3. Place an oil pan under the engine to collect
the used oil.
4. 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 5–7 if the oil filter cartridge is not beingreplaced.5. Remove the oil filter cartridge with an oil filter
wrench.1. Engine oil drain bolt
1. Oil filter cartridge
1. Oil filter wrench
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8-13
8
NOTE:An oil filter wrench is available at a nearby Yamahadealer.
6. 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.
7. Install the new oil filter cartridge with an oil fil-
ter wrench, and then tighten it to the specified
torque with a torque wrench.8. Install the engine oil drain bolt, and then tight-
en it to the specified torque.
9. Add the specified amount of the recommend-
ed engine oil, and then install and tighten the
engine oil filler cap.1. O-ring
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)
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8-14
8
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.
Make sure that no foreign material enters thecrankcase.10. 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.
11. Turn the engine off, wait at least ten minutes,
and then check the oil level and correct it if
necessary.
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. Recommended oil:
See page 10-1.
Oil quantity:
Without oil filter cartridge replacement:
2.20 L (2.33 US qt) (1.94 Imp.qt)
With oil filter cartridge replacement:
2.30 L (2.43 US qt) (2.02 Imp.qt)
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8-15
8
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.To change the final gear oil
1. Remove the final gear case guard by remov-
ing the bolts.
2. Place the ATV on a level surface.
3. Place an oil pan under the final gear case to
collect the used oil.
4. Remove the final gear oil filler bolt and the fi-
nal gear oil drain bolt to drain the oil from the
final gear case.1. Final gear oil
2. Final gear oil filler bolt
3. Correct oil levelTightening torque:
Final gear oil filler bolt:
23 Nm (2.3 m·kgf, 17 ft·lbf)
1. Final gear case guard
2. Bolt
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8-16
8 5. Install the drain bolt, and then tighten it to the
specified torque.
6. Add the recommended final gear oil to the
brim of the filler hole as shown.
CAUTION:ECB00420Be sure no foreign material enters the finalgear case.
7. Install the oil filler bolt, and then tighten it to the
specified torque.
1. Final gear oil drain boltTightening torque:
Final gear oil drain bolt:
23 Nm (2.3 m·kgf, 17 ft·lbf)
1. Final gear oil
2. Final gear oil filler bolt
3. Correct oil levelRecommended final gear oil:
See page 10-1.
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8-17
88. Check the final gear case for oil leakage. If oil
is leaking, check for the cause.
9. Install the final gear case guard by installing
the bolts and tightening them to the specified
torque.
EBU23641Cleaning the air filter element The air filter element should be cleaned at the in-
tervals specified in the periodic maintenance and
lubrication chart. Clean the air filter element more
frequently if you are riding in unusually wet or dusty
areas.
NOTE:There is a check hose at the bottom of the air filter
case. If dust or water collects in this hose, empty
the hose and clean the air filter element and air fil-ter case.
1. Remove the seat. (See page 4-11.)
2. Remove the air filter case cover by unhooking
the holders. Tightening torque:
Final gear oil filler bolt:
23 Nm (2.3 m·kgf, 17 ft·lbf)
Tightening torque:
Final gear case guard bolt:
16 Nm (1.6 m·kgf, 11 ft·lbf)1. Air filter case check hose
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