Page 86 of 130
8-12
82. Check the engine oil level on a cold engine.
NOTE:If the engine was started before checking the oil
level, be sure to warm up the engine sufficiently,
and then wait at least ten minutes until the oil set-tles for an accurate reading.
3. Remove the engine oil filler cap, and then
wipe the dipstick off with a clean rag.
4. Insert the dipstick into the filler hole (without
screwing it in), and then remove it again to
check the oil level.
NOTE:The engine oil should be between the minimumand maximum level marks.
5. If the engine oil is at or below the minimum
level mark, add sufficient oil of the recom-
mended type to raise it to the correct level.
6. Insert the dipstick into the oil filler hole, and
then tighten the engine oil filler cap.
1. Engine oil filler cap
1. Dipstick
2. Maximum level mark
3. Minimum level mark
Page 89 of 130

8-15
8
NOTE:Be sure to wipe off spilled oil on any parts after theengine and exhaust system have cooled down.CAUTION:ECB00300In order to prevent clutch slippage (since the
engine oil also lubricates the clutch), do not
mix any chemical additives. Do not use oils
with a diesel specification of “CD” or oils of
a higher quality than specified. In addition,
do not use oils labeled “ENERGY CONSERV-
ING II” or higher.Make sure that no foreign material enters thecrankcase.10. 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.
11. Turn the engine off, wait at least ten minutes,
and then check the oil level and correct it if
necessary.
EBU23383Final 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.NOTE:The final gear oil level must be checked on a coldengine.
2. Remove the final gear oil filler bolt, and then
check the oil level in the final gear case. Recommended oil:
See page 10-1.
Oil quantity:
Without oil filter cartridge replacement:
2.20 L (2.33 US qt) (1.94 Imp.qt)
With oil filter cartridge replacement:
2.30 L (2.43 US qt) (2.02 Imp.qt)
Page 92 of 130
8-18
88. Check the final gear case for oil leakage. If oil
is leaking, check for the cause.
9. Install the final gear case guard by installing
the bolts and tightening them to the specified
torque.
EBU23433Changing the differential gear oil (4WD
model)The 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. Place the ATV on a level surface.
2. Place an oil pan under the differential gear
case to collect the used oil.3. Remove the differential gear oil filler bolt and
the differential gear oil drain bolt to drain the
oil from the differential gear case. Tightening torque:
Final gear oil filler bolt:
23 Nm (2.3 m·kgf, 17 ft·lbf)
Tightening torque:
Final gear case guard bolt:
16 Nm (1.6 m·kgf, 11 ft·lbf)
1. Differential gear oil filler bolt
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8-19
8 4. Install the drain bolt, and then tighten it to the
specified torque.
5. Refill with the specified amount of the recom-
mended differential gear oil.
NOTE:Do not exceed the specified differential gear oil
quantity when filling. Overfilling will cause the oil
to seep out of the breather hose during and after
riding.
The differential gear case capacity is greater
than the recommended oil quantity, therefore
the oil level cannot be accurately checked fromthe oil filler hole.CAUTION:ECB00410Be sure no foreign material enters the differen-tial gear case.
6. Install the oil filler bolt, and then tighten it to the
specified torque.
7. Check the differential gear case for oil leak-
age. If oil is leaking, check for the cause.
1. Differential gear oil drain boltTightening torque:
Differential gear oil drain bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Recommended differential gear oil:
See page 10-1.
Oil quantity:
YFM350FWA 0.35 L (0.37 US qt) (0.31
Imp.qt)
Tightening torque:
Differential gear oil filler bolt:
23 Nm (2.3 m·kgf, 17 ft·lbf)
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8-22
8
CAUTION:ECB00440Do not twist the sponge material when squeez-ing it.
8. Check the sponge material and replace it if
damaged.
9. Apply a quality foam air filter oil to the sponge
material.NOTE:The sponge material should be wet but not drip-ping.
10. Pull the sponge material over the air filter ele-
ment frame, and then install the lock plate.11. Insert the air filter element into the air filter
case, and then install the air filter case cover
by hooking the holders onto the air filter case.
12. Install the seat.
NOTE:The 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 carburetor fittings and the rubber joint
manifold fittings for an air-tight seal. Tighten all fit-
tings securely to avoid the possibility of unfilteredair entering the engine.CAUTION:ECB00460Make sure that the air filter element is prop-
erly seated in the air filter case.Never operate the engine with the air filter el-
ement removed. This will allow unfiltered air
to enter the engine, causing rapid engine
wear and possible engine damage. Addition-
ally, operation without the air filter element
Page 102 of 130

8-28
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
Page 106 of 130
8-32
83. Install the panel.
EBU24900Checking and lubricating the cables The operation and the condition of all control ca-
bles should be checked before each ride, and the
cables and cable ends should be lubricated if nec-
essary. If a cable is damaged or does not move
smoothly, have a Yamaha dealer check or replace
it.
WARNING
EWB02130Inspect cables frequently and replace if dam-
aged. Corrosion can result when the cable
sheaths become damaged, and cables can
also become frayed or kinked, which could re-
strict the operation of controls and lead to anaccident or injury.EBU28711Checking and lubricating the front and
rear brake levers The operation of the front and rear brake levers
should be checked before each ride, and the lever
pivots should be lubricated if necessary.
1. Brake light switch
2. Brake light switch adjusting nutRecommended lubricant:
Engine oil
Recommended lubricants:
Front brake lever:
Silicone grease
Rear brake lever:
Lithium-soap-based grease
Page 108 of 130

8-34
8
EBU24962Checking 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 play
in a wheel hub or if a wheel does not turn smoothly,
have a Yamaha dealer check the wheel hub bear-
ings.EBU25102Lubricating the steering shaft The steering shaft must be lubricated at the inter-
vals specified in the periodic maintenance and lu-
brication chart.EBU25222Battery This model is equipped with a sealed-type (MF)
battery, which does not require any maintenance.
There is no need to check the electrolyte or to add
distilled water. Check and, if necessary, tighten the
battery lead connections.
CAUTION:ECB00620Never attempt to remove the battery cell seals,as this would permanently damage the battery.
WARNING
EWB02160Battery electrolyte is poisonous and danger-
ous, as it contains sulfuric acid, which can
cause severe burns. Avoid contact with skin,
eyes or clothing. Always shield your eyes
when working near batteries.
Antidote:
EXTERNAL: Flush with water.
INTERNAL: Drink large quantities of water or
milk. Follow with milk of magnesia, beaten egg
or vegetable oil. Call a physician immediately.
EYES: Flush with water for 15 minutes and get
prompt medical attention.
Batteries produce explosive gases. Keep
sparks, flame, cigarettes or other sources of ig-
nition away. Ventilate when charging or using
in an enclosed space.KEEP OUT OF REACH OF CHILDREN. Recommended lubricant:
Lithium-soap-based grease