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82. Check the spark plug for electrode erosion
and excessive carbon or other deposits, and
replace it if necessary.
3. Measure the spark plug gap with a wire thick- ness gauge and, if necessary, adjust the gap
to specification. To install the spark plug
1. Clean the surface of the spark plug gasket and its mating surface, and then wipe off any
grime from the spark plug threads.
2. Install the spark plug with the spark plug wrench, and then tighten it to the specified
torque.
TIPIf a torque wrench is not available when installing
the 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 speci-
fied torque as soon as possible. 3. Install the spark plug cap.EBU30243Engine oil and oil filter cartridgeThe 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
specified in the periodic maintenance chart.
Specified spark plug:
NGK/DR7EA
1. Spark plug gapSpark plug gap:0.6–0.7 mm (0.024–0.028 in)
Tightening torque:Spark plug:18 N·m (1.8 kgf·m, 13 lb·ft)
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13. Check the engine oil filler cap O-ring for dam-
age, and then install the filler cap.
14. Start the engine and let it idle for several mi- nutes while checking for oil leakage. If any oil
leakage is found, immediately turn the engine
off and check for the cause.
15. Turn the engine off, wait at least ten minutes, and then check the oil level and correct it if
necessary.
16. Install panel E.
EBU28566Final gear oilThe 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 speci-
fied in the periodic maintenance and lubrication
chart.
To check the final gear oil level 1. Place the ATV on a level surface.
2. Remove the final gear oil filler bolt and its gas- ket, and then check the oil level in the final
gear case. 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. Check the oil filler bolt gasket for damage, and replace it if necessary.
5. Install the oil filler bolt and its gasket, and then tighten the bolt to the specified torque.
1. Final gear oil filler bolt
2. Gasket
3. Final gear oil
4. Correct oil levelTightening torque:Final gear oil filler bolt:22 N·m (2.2 kgf·m, 16 lb·ft)1
2
3
4
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8
TIPIf the recommended oil is not available, SAE 80W-
90 API GL-5 Hypoid gear oil may be used instead.
However, when using this oil, noise from the final
gear case may occur when applying the rear
brake.
7. Check the oil filler bolt gasket for damage,and replace it if necessary.
8. Install the oil filler bolt and its gasket, and then tighten the bolt to the specified torque.
9. Check the final gear case for oil leakage. If oil is leaking, check for the cause.
10. Install the final gear case guard by installing the bolts, and then tightening them to the
specified torque.EBU23437Changing the differential gear oilThe differential gear case must be checked for oil
leakage before each ride. If any leakage is found,
have a Yamaha dealer check and repair the ATV.
In addition, the differential gear oil must be
changed as follows at the intervals specified in the
periodic maintenance and lubrication chart.
1. Final gear oil filler bolt
2. Gasket
3. Final gear oil
4. Correct oil levelRecommended final gear oil:See page 10-1.1
2
3
4
Tightening torque: Final gear oil filler bolt:22 N·m (2.2 kgf·m, 16 lb·ft)
Tightening torque: Final gear case guard bolt:8 N·m (0.8 kgf·m, 5.9 lb·ft)
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8
TIPDo not exceed the specified differential gear oil
quantity when filling. Overfilling will cause the oil
to seep out of the breather hose during and af-
ter riding.
The differential gear case capacity is greater
than the recommended oil quantity, therefore
the oil level cannot be accurately checked from
the oil filler hole. 6. Check the oil filler bolt gasket for damage,
and replace it if necessary.
7. Install the oil filler bolt and its gasket, and then tighten the bolt to the specified torque.
8. Check the differential gear case for oil leak- age. If oil is leaking, check for the cause.
EBU23471CoolantThe coolant level should be checked before each
ride. In addition, the coolant must be changed at
the intervals specified in the periodic maintenance
and lubrication chart.EBU27129To check the coolant level1. Place the ATV on a level surface.TIPThe coolant level must be checked on a cold en-
gine since the level varies with engine tempera-
ture. 2. Check the coolant level in the coolant reser- voir.TIPThe coolant should be between the minimum and
maximum level marks.
Recommended differential gear oil:See page 10-1.
Oil quantity: 0.35 L (0.37 US qt, 0.31 Imp.qt)
Tightening torque: Differential gear oil filler bolt:23 N·m (2.3 kgf·m, 17 lb·ft)
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EBU29703Adjusting the throttle lever free playThe 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.1. Slide the rubber cover back.
2. Loosen the locknut.
3. To increase the throttle lever free play, turn the throttle lever free play adjusting bolt in di-
rection (a). To decrease the throttle lever free
play, turn the adjusting bolt in direction (b).
4. Tighten the locknut.
5. Slide the rubber cover to its original position.
EBU24061Valve clearanceThe 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. Throttle lever free play
2. Rubber cover
3. Locknut
4. Throttle lever free play adjusting bolt2
4 3
1
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EBU29602BrakesReplacement of brake components requires pro-
fessional knowledge. Brake service should be
performed by a Yamaha dealer.
WARNING
EWB02572Operating with improperly serviced or adjust-
ed brakes could lead to a loss in braking ability
and an accident. EBU28414Checking the front brake pads and rear
brake friction platesThe 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.
EBU24172Front 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 8-61.) 1. Lining thickness
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EBU30321Rear 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.EBU29844Checking the brake fluid levelBefore riding, check that the brake fluid is above
the minimum level mark. Replenish the brake fluid
if necessary.TIPStraighten the handlebars for an accurate reading.
NOTICEECB01161Brake 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 or brake sys-
tem leakage. Therefore, be sure to check the
brake pads for wear and the brake system for
leakage. If the brake fluid level suddenly goes
down, have a Yamaha dealer the brake system
before further riding.
WARNING
EWB02721Improper 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.
1. Minimum level mark
1
Specified brake fluid:
DOT 4
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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 flu-
id and may result in vapor lock.
EBU24283Changing the brake fluidHave a Yamaha dealer change the brake fluid at
the intervals specified in 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 damaged or leaking.
Oil seals: Replace every two years.
Brake hoses: Replace every four years.
EBU24395Checking the front brake lever free
playThe 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.1. No brake lever free play
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