2008 YAMAHA GRIZZLY 350 engine

8-13
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
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. Refill with the specified amount of the recom-
mended engine oil, and then install and tight-
en 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
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.
EBU23383Final 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 5. Pull off the air filter element lock plate, and
then remove the sponge material from the air
filter element frame.6. 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.
7. 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.
8. Check the sponge material and replace it if
damaged.
9. Apply a quality foam air filter oil to the sponge
material.NOTE:The sponge material should be wet but not drip-ping.
10. Pull the sponge material over the air filter ele-
ment frame, and then install the lock plate.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.
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.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.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-
1. V-belt cooling duct check hose (left front side of ATV)
1. V-belt case drain plug

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8sional 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).
1. Throttle stop screwEngine idling speed:
1450–1550 r/min

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8
NOTE:If the specified idling speed cannot be obtained as
described above, have a Yamaha dealer make theadjustment.EBU24044Adjusting 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 throttle cable free play adjusting bolt in di-
rection (a). To decrease the throttle cable free
play, turn the adjusting bolt in direction (b).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.1. Locknut
2. Throttle cable free play adjusting bolt
3. Throttle cable free play