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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 or
damage to the engine.EBU24010Adjusting 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.
TIPA diagnostic tachometer is needed to make this
adjustment.1. Start the engine and warm it up.TIPThe engine is warm when it quickly responds to the
throttle.2. Remove panel C. (See page 8-10.)
3. Attach the tachometer to the spark plug lead.
4. 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).
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TIPIf the specified idling speed cannot be obtained as
described above, have a Yamaha dealer make the
adjustment.5. Install the panel.
EBU24047Adjusting the throttle lever free play The throttle lever free play should be checked and,
if necessary, adjusted at the intervals specified in
the periodic maintenance and lubrication chart.
The throttle lever free play should measure 3.0–
5.0 mm (0.12–0.20 in) as shown. Periodically
check the throttle lever free play and, if necessary,
adjust it as follows.TIPThe engine idling speed must be checked, and ad-
justed if necessary, before adjusting the throttle le-
ver free play.1. Slide the rubber cover back.
2. Loosen the locknut.
3. To increase the throttle lever free play, turnthe throttle lever free play adjusting bolt in di-
rection (a). To decrease the throttle lever free
play, turn the adjusting bolt in direction (b).
1. Throttle stop screwEngine idling speed:1450–1550 r/min
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84. 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.
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.EBU29601Brakes Replacement of brake components requires pro-
fessional knowledge. Brake service should be per-
formed by a Yamaha dealer.
WARNING
EWB02571Operating with improperly serviced or adjust-
ed brakes could lead to a loss in braking ability
and an accident.
1. Rubber cover
2. Throttle lever free play adjusting bolt
3. Locknut
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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 gear
case.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 the
brake pads. (See page 8-62.)EBU30320Rear brake friction plates
The rear brake friction plates must be checked
and, if necessary, replaced by a Yamaha dealer at
the intervals specified in the periodic maintenance
and lubrication chart.1. Lining thickness
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EBU29841Checking the brake fluid level Before riding, check that the brake fluid is above
the minimum level mark. Check the brake fluid lev-
el with the top of the reservoir level. Replenish the
brake fluid if necessary.
WARNING
EWB02720Improper maintenance can result in loss of
braking ability. Observe these precautions:
●Insufficient brake fluid may allow air to enter
the brake system, reducing braking perfor-
mance.●Clean the filler cap before removing. Use
only DOT 4 brake fluid from a sealed contain-
er.●Use only the specified brake fluid; otherwise,
the rubber seals may deteriorate, causing
leakage.●Refill with the same type of brake fluid. Add-
ing a brake fluid other than DOT 4 may result
in a harmful chemical reaction.●Be careful that water does not enter the
brake fluid reservoir when refilling. Water
will significantly lower the boiling point of
the fluid and may result in vapor lock.NOTICEECB01160Brake fluid may damage painted surfaces or
plastic parts. Always clean up spilled fluid im-
mediately.As the brake pads wear, it is normal for the brake
fluid level to gradually go down. A low brake fluid
level may indicate worn brake pads and/or brake
system leakage; therefore, be sure to check the
1. Minimum level markSpecified brake fluid:DOT 4
1
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8
brake pads for wear and the brake system for leak-
age. If the brake fluid level goes down suddenly,
have a Yamaha dealer check the cause before fur-
ther riding.
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.EBU24394Checking 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.
EBU30343Adjusting the rear brake lever and
brake pedal free pl ay, and the brake
pedal height The rear brake lever and brake pedal free play,
and the brake pedal height must be checked and,
if necessary, adjusted at the intervals specified in
the periodic maintenance and lubrication chart.
Adjusting the brake lever free play
The brake lever free play should measure 10.0 mm
(0.39 in). If the free play is incorrect, adjust it as fol-
lows.1. No brake lever free play
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8
2. To increase the brake pedal free play, turn the
brake pedal free play adjusting nut in direction
(a). To decrease the brake pedal free play,
turn the adjusting nut in direction (b).
3. Tighten the locknut.
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. Locknut
2. Brake pedal free play adjusting nut
21
(a)
(b)
1. Front axle boot (each side)
1. Rear axle boot (each side)
1
1
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EBU28871Checking and lubricating the brake
pedal The operation of the brake pedal should be
checked before each ride, and the pedal pivot
should be lubricated if necessary.EBU24963Checking the wheel hub bearings The front and rear wheel hub bearings must be
checked at the intervals specified in the periodic
maintenance and lubrication chart. If there is playin a wheel hub or if a wheel does not turn smoothly,
have a Yamaha dealer check the wheel hub bear-
ings.
EBU24972Lubricating the drive shaft universal
joint The drive shaft universal joint must be lubricated at
the intervals specified in the periodic maintenance
and lubrication chart.TIPFor parts equipped with a grease nipple, use a
grease gun.
Recommended lubricant:
Lithium-soap-based grease
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