2009 YAMAHA GRIZZLY 350 maintenance

8-21
87. Check the differential gear case for oil leak-
age. If oil is leaking, check for the cause.
EBU23645Cleaning the air filter element The air filter element should be cleaned at the in-
tervals specified in the periodic maintenance and
lubrication chart. Clean or, if necessary, replace
the air filter element more frequently if you are
riding in unusually wet or dusty areas.TIPThere 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. Place the ATV on a level surface.
2. Remove the seat. (See page 4-17.)
3. Remove the air filter case cover by unhooking
the air filter case cover holders. Tightening torque:
Differential gear oil filler bolt:
23 Nm (2.3 m·kgf, 17 ft·lbf)
1. Air filter case check hose
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8-24
8 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.
TIPThe 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.NOTICEECB00460
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 elementwill affect carburetor jetting with subsequent
poor performance and possible engine over-
heating.EBU27081Cleaning the spark arrester Be sure the exhaust pipe and muffler are cool be-
fore cleaning the spark arrester.
1. Remove the bolts.
2. Remove the tailpipe by pulling it out of the
muffler.1. Bolt
2. Tailpipe
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8
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.TIPIf 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-
sional knowledge and experience. The adjustment
described in the following section, however, may
be performed by the owner as part of routine main-
tenance.NOTICEECB00480The 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.
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8
EBU24045Adjusting 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.TIPThe engine idling speed must be checked, and ad-
justed if necessary, before adjusting the throttle ca-ble free play.
1. Slide the rubber cover back.
2. Loosen the locknut.
3. 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).4. Tighten the locknut.
5. Slide the rubber cover to its original position.
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. Rubber cover
2. Throttle cable free play adjusting bolt
3. Locknut
4. Throttle cable free play
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8
EBU24071Adjusting 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 by a Yamaha dealer at the
intervals specified in the periodic maintenance and
lubrication chart.EBU28413Checking the front brake pads and rear
brake friction plates The front brake pads and the rear brake friction
plates must be checked for wear at the intervals
specified in the periodic maintenance and lubrica-
tion chart.TIPThis ATV is equipped with a wet, multiple-disc type
rear brake, which is located inside of the final gearcase.
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.TIPThe wheels need to be removed to check thebrake pads. (See page 8-47.)1. Brake pad
2. Lining thickness
2
1
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8

Use only the recommended quality brake fluid,
otherwise the rubber seals may deteriorate,
causing leakage and poor braking performance.
Refill with the same type of brake fluid. Mixing
fluids may result in a harmful chemical reaction
and lead to poor braking performance.
Be careful that water does not enter the brake
fluid reservoir when refilling. Water will signifi-
cantly lower the boiling point of the fluid and may
result in vapor lock.
Brake fluid may deteriorate painted surfaces or
plastic parts. Always clean up spilled fluid imme-
diately.
As the brake pads wear, it is normal for the brake
fluid level to gradually go down. However, if the
brake fluid level goes down suddenly, have a
Yamaha dealer check the cause.EBU24281Changing the brake fluid Have a Yamaha dealer change the brake fluid at
the intervals specified in the TIP after the periodic
maintenance and lubrication chart. In addition,have the oil seals of the brake master cylinder and
calipers as well as the brake hoses replaced at the
intervals listed below or whenever they are dam-
aged or leaking.

Oil seals: Replace every two years.
Brake hoses: Replace every four years.EBU24393Checking the front brake lever free play The brake lever free play must be checked at the
intervals specified in the periodic maintenance and
lubrication chart. The brake lever should have no
free play as shown. If there is free play, have a
Yamaha dealer check the brake system. Recommended brake fluid:
DOT 41. Brake lever free play
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8
WARNING
EWB02471Operating with improperly serviced or adjust-
ed brakes could cause loss of braking ability,
which could lead to an accident.
After servicing:
Make sure the brakes operate smoothly and
that there is no free play.
Make sure the brakes do not drag.
Make sure the brakes are not spongy. All air
must be bled from the brake system.
Replacement of brake components requires
professional knowledge. These proceduresshould be performed by a Yamaha dealer.EBU28635Adjusting the brake pedal and rear
brake lever free play and checking the
brake pedal position The brake pedal and brake lever free play and the
brake pedal position must be checked and, if nec-
essary, adjusted at the intervals specified in the
periodic maintenance and lubrication chart.
TIP
Always perform this maintenance completely in
the following order whenever adjusting the rear
brake.
When adjusting the rear brake, be sure to adjust
both the brake pedal and the brake lever.
Before adjusting the brake lever and brake pedal
free play, check the rear brake friction plates forwear.
Adjusting the brake pedal and brake lever free
play
The brake pedal free play should measure 17.0–
20.0 mm (0.67–0.79 in). The brake lever free play
should measure 8.0–10.5 mm (0.31–0.41 in). If ei-
ther free play is incorrect, adjust it as follows.
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8
WARNING
EWB02080Operating with improperly serviced or adjust-
ed brakes could cause loss of braking ability,
which could lead to an accident.
After servicing:
Make sure the brakes operate smoothly and
that the free play is correct.
Make sure the brakes do not drag.
Replacement of brake components requires
professional knowledge. These proceduresshould be performed by a Yamaha dealer.
EBU24230Axle boots The axle boots must be checked for damage at the
intervals specified in the periodic maintenance and
lubrication chart. Check the axle boots for tears or
damage. If any damage is found, have them re-
placed by a Yamaha dealer.
1. Distance between brake pedal and footboard
1. Front axle boot (each side)
U4S262E0.book Page 36 Tuesday, June 10, 2008 11:40 AM