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8-15
8
To install the cowling
1. Place the cowling in the original position, and
then tighten the quick fasteners.
2. Install panels C, B and A.EBU29441Checking the spark plug The spark plug is an important engine component,
which should be checked periodically, preferably
by a Yamaha dealer. Since heat and deposits will
cause any spark plug to slowly erode, the spark
plug should be removed and checked in accor-
dance with the periodic maintenance and lubrica-
tion chart. In addition, the condition of the spark
plug can reveal the condition of the engine.
The porcelain insulator around the center elec-
trode of the spark plug should be a medium-to-light
tan (the ideal color when the vehicle is ridden nor-
mally). If the spark plug shows a distinctly different
color, the engine could be operating improperly.
Do not attempt to diagnose such problems your-
self. Instead, have a Yamaha dealer check the ve-
hicle.
If the spark plug shows signs of electrode erosion
and excessive carbon or other deposits, it should
be replaced.
1. Quick fastener
1. Quick fastener
11
1
1
U18P67E0.book Page 15 Wednesday, May 9, 2012 3:30 PM
Page 104 of 156
8-16
8Before installing the spark plug, the spark plug gap
should be measured with a wire thickness gauge
and, if necessary, adjusted to specification.
Clean the surface of the spark plug gasket and its
mating surface, and then wipe off any grime from
the spark plug threads.
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 specified
torque as soon as possible.EBU29499Engine oil and oil filter element The engine oil level should be checked before
each ride. In addition, the oil must be changed and
the oil filter element replaced at the intervals spec-
ified in the periodic maintenance and lubrication
chart.
To check the engine oil level
1. Place the ATV on a level surface.
2. Start the engine, warm it up until the engine oil has reached a normal temperature of 40 °C
(104 °F), let it continue to idle for ten seconds
or more, and then turn the engine off.
Specified spark plug:
NGK/CR8E
1. Spark plug gapSpark plug gap:0.7–0.8 mm (0.028–0.031 in)
Tightening torque:Spark plug:13 Nm (1.3 m·kgf, 9.4 ft·lbf)
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Page 110 of 156
8-22
815. Install the engine guard by installing the bolts,
and then tighten them to the specified torque.
NOTICE: Be sure to apply LOCTITE
® to the
engine guard bolts before installing them.
[ECB00371]
EBU29860
Coolant The 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. Have a Yamaha dealer
change the coolant. WARNING! Never attempt to
remove the radiator cap when the engine is
hot.
[EWB02670]
EBU27942
To check the coolant level 1. 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.
Tightening torque:Engine guard bolt:7 Nm (0.7 m·kgf, 5.1 ft·lbf)
1. Coolant reservoir cap
2. Maximum level mark
3. Minimum level mark
1
2
3
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8-23
8
3. If the coolant is at or below the minimum level
mark, remove the coolant reservoir cap, add
coolant or distilled water to the maximum level
mark, and then install the reservoir cap.
NOTICE: If coolant is not available, use
distilled water or soft tap water instead. Do
not use hard water or salt water since they
are harmful to the engine. If water has
been used instead of coolant, replace it
with coolant as soon as possible, other-
wise the cooling system will not be pro-
tected against frost and corrosion. If water
has been added to the coolant, have a
Yamaha dealer check the antifreeze con- tent of the coolant as soon as possible,
otherwise the effectiveness of the coolant
will be reduced.
[ECB01011]
TIP●The radiator fan is automatically switched on or
off according to the coolant temperature in the
radiator.
●If the engine overheats, see page 8-54 for fur-
ther instructions.EBU26806Cleaning 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.
Coolant reservoir capacity (up to the maxi-
mum level mark): 0.25 L (0.26 US qt, 0.22 Imp.qt)
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8-27
8
15. Insert the air filter element into the air filter
case, and then tighten the wing bolt. NOTICE:
Make sure that the air filter element is
properly seated in the air filter case. Never
operate the engine with the air filter ele-
ment removed. This will allow unfiltered air
to enter the engine, causing rapid engine
wear and possible engine damage. Addi-
tionally, operation without the air filter ele-
ment will affect the fuel injection system
with subsequent poor performance and
possible engine overheating.
[ECB00761]
16. Install the air filter case cover by hooking the holders onto the air filter case. 17. 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 throttle body and the rubber joint mani-
fold fittings for an air-tight seal. Tighten all fittings
securely to avoid the possibility of unfiltered air en-
tering the engine.EBU27703Cleaning the spark arrester Select a well-ventilated area free of combustible
materials and make sure the exhaust and muffler
are cool.
1. Remove the tailpipe bolt.
1. Washer
1
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Page 117 of 156
8-29
8
7. Start the engine and rev it up approximately
twenty times while momentarily creating ex-
haust system back pressure by blocking the
end of the muffler with a shop towel.
8. Stop the engine and allow the exhaust pipe to cool.
9. Check the gasket for damage, and replace it if necessary.
10. Install the gasket and the purging bolt, and then tighten the bolt to the specified torque.
WARNING
EWB02380Never run the engine in an enclosed area when
purging the spark arrester, otherwise it could
cause injury to the eyes, burns, carbon monox-
ide poisoning, possibly leading to death, and
start a fire.●Always let the exhaust system cool prior to
touching exhaust components.●Always wear eye protection, and make sure
no one is behind the ATV.●Make sure there are no combustible materi-
als in the area.EBU29702Adjusting 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.
1. Purging bolt
2. Gasket
2
1
Tightening torque: Purging bolt:27 Nm (2.7 m·kgf, 20 ft·lbf)
U18P67E0.book Page 29 Wednesday, May 9, 2012 3:30 PM
Page 118 of 156
8-30
8The throttle lever free play should measure 2.0–
4.0 mm (0.08–0.16 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.
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.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.EBU24130Checking the front a
nd rear brake pads The front and rear brake pads must be checked for
wear at the intervals specified in the periodic main-
tenance and lubrication chart.
1. Rubber cover
2. Throttle lever free play adjusting bolt
3. Locknut
4. Throttle lever free play
32
4
(a)(b)
1U18P67E0.book Page 30 Wednesday, May 9, 2012 3:30 PM
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8
EBU29501Checking 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.
Front brakeRear brake
TIPTo check the rear brake fluid level, remove the
seat. (See page 4-10.)
WARNING
EWB02720Improper maintenance can result in loss of
braking ability. Observe these precautions:
1. Minimum level mark
1
1. Minimum level markSpecified brake fluid:
DOT 4
1
U18P67E0.book Page 32 Wednesday, May 9, 2012 3:30 PM
