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8-23
8
TIPIf the spark plug shows a distinctly different color,
the engine could be operating improperly. Do not
attempt to diagnose such problems yourself. In-
stead, have a Yamaha dealer check the ATV.2. 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. Specified spark plug:
NGK/LMAR6A-9
1. Spark plug gapSpark plug gap:
0.8–0.9 mm (0.031–0.035 in)
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8-24
8
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.3. Install the spark plug cap.EBU27466Engine oil and oil filter cartridge The 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 spec-
ified in the periodic maintenance and lubrication
chart.
To check the engine oil level
1. Place the ATV on a level surface.
2. Check the engine oil level on a cold engine.
TIPIf the engine was started before checking the oil
level, be sure to warm up the engine sufficiently,
and then wait at least 10 minutes until the oil settles
for an accurate reading.3. Remove panel F. (See page 8-10.)
4. Remove the engine oil dipstick, and then wipe
it off with a clean rag.
5. Insert the dipstick completely into the oil filler
hole, and then remove it again to check the oil
level. Tightening torque:
Spark plug:
13 Nm (1.3 m·kgf, 9.4 ft·lbf)1. Engine oil dipstick
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8-28
8
Make sure that no foreign material enters the
crankcase.12. Start the engine, and then let it idle for several
minutes while checking it for oil leakage. If oil
is leaking, immediately turn the engine off and
check for the cause.
13. Turn the engine off, wait at least ten minutes,
and then check the oil level and correct it if
necessary.
14. Install panel F.EBU27306Final gear oil The 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 specified
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 level check bolt and
its gasket, and then check the oil level in the
final gear case. The oil level should be at the
brim of the check hole.3. If the oil is below the brim of the check hole,
remove the final gear oil filler bolt and its gas-
ket, and then add sufficient oil of the recom-
mended type to raise it to the correct level.
1. Final gear oil
2. Gasket
3. Final gear oil level check bolt
4. Correct oil level
1
243
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8-33
8 8. Check the differential gear case for oil leak-
age. If oil is leaking, check for the cause.
EBU23470Coolant 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.EBU27125To 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.
3. If the coolant is at or below the minimum level
mark, remove panel D to access the coolant
reservoir. (See page 8-10.)
4. Remove the coolant reservoir cap, add cool-
ant or distilled water to the maximum level
mark, install the reservoir cap, and then install
the panel. NOTICE: If coolant is not avail-
able, use distilled water or soft tap water
instead. Do not use hard water or salt wa-
ter since they are harmful to the engine. If
water has been used instead of coolant, re-
place it with coolant as soon as possible,
otherwise the cooling system will not be1. Maximum level mark
2. Minimum level mark
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8-34
8protected 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]
TIPThe radiator fan is automatically switched on or
off according to the coolant temperature in the
radiator.If the engine overheats, see page 8-66 for fur-
ther instructions.EBU27764To change the coolant
WARNING
EWB01890Wait for the engine and radiator to cool before
removing the radiator cap. You could be
burned by hot fluid and steam blown out under
pressure. Always place a thick rag over the cap
when opening. Allow any remaining pressure
to escape before completely removing the cap.1. Place the ATV on a level surface.
2. Remove panels D and F. (See page 8-10.)
3. Place a container under the engine, and then
remove the coolant drain bolt and its gasket.
(Use a trough or a similar object as shown to
prevent coolant from spilling on the engine
guard.)
1. Coolant reservoir cap
2. Maximum level mark
3. Minimum level markCoolant reservoir capacity (up to the maxi-
mum level mark):
0.24 L (0.25 US qt, 0.21 Imp.qt)
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8-38
818. When coolant begins to flow out of the bolt
hole, tighten the cylinder head air bleed bolt to
the specified torque.
19. Start the engine and let it idle for ten minutes.
20. Rev the engine five times.
21. Pour the recommended coolant into the radia-
tor until it is full.22. Stop the engine and allow it to cool. If the cool-
ant level has dropped after the engine has
cooled, add sufficient coolant until it reaches
the top of the radiator, and then install the ra-
diator cap.
23. Start the engine, and then check for coolant
leakage.
TIPIf any leakage is found, have a Yamaha dealer
check the cooling system.24. Install the V-belt cooling duct, and then tighten
the clamp screw.
25. Install the panels.EBU27805Cleaning 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 are two check hoses at the bottom of the air
filter case, which are located behind panels D and
E. (See page 8-10 for an explanation on removing
1. Cylinder head air bleed boltTightening torque:
Cylinder head air bleed bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
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8-41
8 8. Check the sponge material and replace it if
damaged.
9. Apply Yamaha foam air filter oil or other qual-
ity foam air filter oil to the sponge material.
TIPThe sponge material should be wet but not drip-
ping.10. Install the mesh and the sponge material into
the air filter case. NOTICE: Make sure that
the air filter element is properly seated in
the air filter case. Never operate the engine
with the air filter element removed. This
will allow unfiltered air to enter the engine,
causing rapid engine wear and possibleengine damage. Additionally, operation
without the air filter element will affect the
fuel injection system with subsequent
poor performance and possible engine
overheating.
[ECB00761]
11. Insert the projections on the air filter case cov-
er into the holders on the air filter case, and
then install the air filter case cover by hooking
the holders onto the cover.
12. Place the hoses in their original position as
shown.1. Air filter case cover
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8-42
813. Install the panel.
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.
EBU27812Cleaning the spark arrester Select a well-ventilated area free of combustible
materials and make sure the exhaust and muffler
are cool.
1. Remove the bolts.
2. Remove the tailpipe by pulling it out of the
muffler, and then remove the gasket.
3. Tap the tailpipe lightly, and then use a wire
brush to remove any carbon deposits from the
spark arrester portion of the tailpipe and inside
of the tailpipe housing.
1. Hose
1
1. Bolt
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