2008 YAMAHA GRIZZLY 350 Owners Manual

8-23
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

8-24
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

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8
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.EBU24120Checking the front brake pads and rear
brake shoes The front brake pads and the rear brake shoes
must be checked for wear at the intervals specified
in the periodic maintenance 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.
NOTE:The wheels need to be removed to check thebrake pads. (See page 8-38.)EBU24180Rear brake shoes
The rear brake is provided with a wear indicator,
which allows you to check the brake shoe wear
without having to disassemble the brake. To check
the brake shoe wear, check the position of the
wear indicator while applying the brake. If a brake1. Brake pad
2. Lining thickness

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8 shoe has worn to the point that the wear indicator
reaches the wear limit line or mark, have a
Yamaha dealer replace the brake shoes as a set.
EBU24251Checking the brake fluid level Insufficient brake fluid may allow air to enter the
brake system, possibly causing it to become inef-
fective.
Before riding, check that the brake fluid is above
the minimum level mark and replenish if neces-
sary. A low brake fluid level may indicate wornbrake pads and/or brake system leakage. If the
brake fluid level is low, be sure to check the brake
pads for wear and the brake system for leakage.
Front brake1. Wear limit line
2. Wear indicator
1. Minimum level mark

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8Rear brake
Observe these precautions:

When checking the fluid level, make sure that
the top of the brake fluid reservoir is level.
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.EBUM0120Changing the brake fluid Have a Yamaha dealer change the brake fluid at
the intervals specified in the NOTE after the peri-
odic maintenance and lubrication chart. In addi-
tion, have the oil seals of the front brake master
cylinder, equalizer master cylinder and calipers as
well as the brake hoses replaced at the intervals
listed below or whenever they are damaged or
leaking.
Oil seals: Replace every two years.
Brake hoses: Replace every four years.
Brake equalizer piston seals and o-ring: Replace
every two years.
1. Minimum level mark
2. Maximum level markRecommended brake fluid:
DOT 4

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8
EBU24390Checking 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 a
free play of zero mm (zero in) as shown. If the free
play is incorrect, have a Yamaha dealer check the
brake system.
WARNING
EWB02070Operating 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.
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.EBUM0142Checking the rear brake lever and
brake pedal free play and the brake
pedal position The brake pedal and rear brake lever free play,
and brake pedal position must be checked at the
intervals specified in the periodic maintenance and
lubrication chart.
Checking the rear brake lever and brake pedal
free play
The brake lever should have a free play of 3.0–5.0
mm (0.12–0.20 in) as shown. If the free play is in-
correct, have a Yamaha dealer check the brake
system.
1. Brake lever free play

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8The brake pedal should have a free play of 0.0–
12.0 mm (0.00–0.47 in) as shown. If the free play
is incorrect, have a Yamaha dealer check the
brake system.Checking the brake pedal position
The top of the brake pedal should be positioned
72.0–82.0 mm (2.83–3.23 in) above the footboard
bracket. If the brake pedal position is incorrect,
have a Yamaha dealer adjust it.
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.
1. Brake lever free play
1. Brake pedal free play
1. Distance between brake pedal and footboard bracket
1 1