8-15
1
2
3
4
5
6
78
9
10
11
CAUTION:
ECB00440
Do not twist the sponge material when squeez-
ing it.
6. Check the sponge material and replace it if
damaged.
7. Apply a quality foam air filter oil to the sponge
material.
NOTE:
The sponge material should be wet but not drip-
ping.
8. Install the sponge material into the air filter el-
ement.
9. Place the air filter element in the original posi-
tion, and then hook the holder.
10. Install the air filter case cover by hooking the
holders onto the air filter case.
11. Install the panel by installing the bolts.
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.
CAUTION:
ECB00460
Make 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
will affect carburetor jetting with subsequent
poor performance and possible engine over-
heating.
EBU23850
Removing the air intake restrictor plate
To obtain full engine performance capability, re-
moving the air intake restrictor plate is required.
1. Remove the air filter element. (See
page 8-12.)
2. Remove the air intake restrictor plate.
8-17
1
2
3
4
5
6
78
9
10
11
4. Insert the tailpipe into the muffler and align the
screw holes.
5. Install the screws and tighten them.
WARNING
EWB02340
Do not start the engine when cleaning the
spark arrester, otherwise it could cause injury
to the eyes, burns, carbon monoxide poison-
ing, possibly leading to death, and start a fire.
Always let the exhaust system cool prior to
touching exhaust components.
EBU23940
Adjusting 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.
CAUTION:
ECB00480
The 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.
EBU24000
Adjusting 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-
1. Tailpipe
2. Spark arrester
3. Screw
21
3
8-18
1
2
3
4
5
6
78
9
10
11
tion chart.
NOTE:
A diagnostic tachometer is needed to make this
adjustment.
1. Start the engine and warm it up.
NOTE:
The engine is warm when it quickly responds to the
throttle.
2. Attach the tachometer to the spark plug lead.
3. 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).
NOTE:
If the specified idling speed cannot be obtained as
described above, have a Yamaha dealer make the
adjustment.
EBU27071
Checking the throttle cable free play
The throttle cable free play should be checked at
the intervals specified in the periodic maintenance
and lubrication chart.
1. Throttle stop screw
Engine idling speed:
1700–1900 r/min
1 (a) (b)
8-19
1
2
3
4
5
6
78
9
10
11
The throttle cable free play should measure 1.0–
3.0 mm (0.04–0.12 in) at the throttle lever. Period-
ically check the throttle cable free play and, if nec-
essary, have a Yamaha dealer adjust it.
EBU24050
Timing chain
The timing chain stretches with use, resulting in im-
proper valve timing and engine noise. To prevent
this from occurring, the timing chain tensioner
must be adjusted by a Yamaha dealer at the inter-
vals specified in the periodic maintenance and lu-
brication chart.
EBU24060
Valve 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.
EBU24090
Checking the front and rear brake
shoes
The front and rear brake shoes must be checked
for wear at the intervals specified in the periodic
maintenance and lubrication chart. Each brake is
provided with a wear indicator, which allows you to
check the brake shoe wear without having to dis-
assemble the brake. To check the brake shoe
wear, check the position of the wear indicator while
applying the brake. If a brake shoe has worn to the
point that the wear indicator reaches the wear limit
line or mark, have a Yamaha dealer replace the
brake shoes as a set.
1. Throttle lever free play
1
8-25
1
2
3
4
5
6
78
9
10
11
EBU24781
Adjusting the clutch free play
The clutch free play must be adjusted periodically.
Adjust the free play as follows.
1. Remove the rubber cap.
2. Loosen the locknut.
3. Slowly turn the adjusting bolt clockwise until
resistance is felt, and then turn it 1/8 counter-
clockwise.
NOTE:
Turning the adjusting bolt in decreases clutch free
play and turning it out increases clutch free play.
4. Tighten the locknut to the specified torque.
NOTE:
When tightening the locknut, hold the adjusting
bolt with a screwdriver so that the adjusting bolt
does not turn together with the locknut.
5. Install the rubber cap securely.
EBU24900
Checking 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.
1. Rubber cap
2. Locknut
3. Adjusting bolt
1
2
3
Tightening torque:
Locknut:
8 Nm (0.8 m·kgf, 5.8 ft·lbf)
Recommended lubricant:
Engine oil
8-34
1
2
3
4
5
6
78
9
10
11
EBU25791
Troubleshooting chart
Check the fuel level in
the fuel tank.1. Fuel
There is enough fuel.
There is no fuel.
Check the compression.
Supply fuel.
The engine does not start.
Check the compression.
Operate the electric starter.2. Compression
There is compression.
There is no compression.
Check the ignition.
Have a Yamaha dealer
check the ATV.
Remove the spark plug
and check the electrodes.3. Ignition
Wipe off with a dry cloth and correct the
spark plug gap, or replace the spark plug.
Have a Yamaha dealer check the ATV.
The engine does not start.
Have a Yamaha dealer
check the ATV.
The engine does not start.
Check the battery.
Operate the electric starter.4. Battery
The engine turns over
quickly.
The engine turns over
slowly.
The battery is good.Check the electrolyte level, recharge the
battery and check the lead connections.
DryWet
Open the throttle halfway and operate
the electric starter.
INDEX
A
Accessories and loading ................................................ 6-6
Air filter element, cleaning ............................................ 8-12
Air intake restrictor plate, removing.............................. 8-15
B
Battery .................................................................. 5-6
,
8-28
Brake and shift pedals, checking and lubricating ......... 8-27
Brake lever and brake pedal free play (rear),
adjusting..................................................................... 8-22
Brake lever free play, adjusting the front...................... 8-20
Brake lever, front ............................................................ 4-4
Brake levers, checking and lubricating......................... 8-26
Brake pedal and rear brake lever ................................... 4-5
Brakes, front and rear .................................................... 5-3
Brake shoes, checking the front and rear .................... 8-19
C
Cables, checking and lubricating ................................. 8-25
Carburetor, adjusting.................................................... 8-17
Chassis fasteners........................................................... 5-6
Choke ........................................................................... 4-10
Cleaning ......................................................................... 9-1
Clutch free play, adjusting ............................................ 8-25
E
Engine break-in .............................................................. 6-4
Engine, cold start ........................................................... 6-1
Engine idling speed ...................................................... 8-17Engine oil ............................................................... 5-3
,
8-8
Engine, starting a warm ................................................. 6-3
Engine stop switch ......................................................... 4-2
F
Final gear oil......................................................... 5-3
,
8-11
Fuel ........................................................................ 4-7
,
5-3
Fuel cock ........................................................................ 4-8
Fuel tank cap.................................................................. 4-7
Fuse, replacing............................................................. 8-31
H
Handlebar switches ........................................................ 4-2
I
Identification numbers .................................................. 11-1
Indicator light .................................................................. 4-1
Instruments, lights and switches .................................... 5-6
K
Key identification number ............................................. 11-1
Knuckle shafts, lubricating ........................................... 8-27
L
Label locations ............................................................... 2-1
M
Main switch .................................................................... 4-1
Model label ................................................................... 11-2
N
Neutral indicator light ..................................................... 4-1