Page 112 of 156

8-28
813. Pour the recommended coolant into the radia-
tor until it is full.
CAUTION:ECB00400If coolant is not available, use distilled water
or soft tap water instead. Do not use hard wa-
ter or salt water since it is harmful to the en-
gine.If water has been used instead of coolant, re-
place it with coolant as soon as possible,
otherwise the engine may not be sufficiently
cooled and the cooling system will not be
protected 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, oth-
erwise the effectiveness of the coolant willbe reduced.
14. Install the radiator cap, start the engine, let it
idle for several minutes, and then turn it off.
15. Remove the radiator cap to check the coolant
level in the radiator. If it is low, add sufficient
coolant until it reaches the top of the radiator,
and then install the radiator cap.
16. Start the engine, and then check for coolant
leakage.
NOTE:If any leakage is found, have a Yamaha dealercheck the cooling system.
17. Install the panels and the front carrier.EBU23660Cleaning the air filter element The air filter element should be cleaned at the in-
tervals specified in the periodic maintenance and
lubrication chart. Clean the air filter element more
frequently if you are riding in unusually wet or dusty
areas. Antifreeze/water mixture ratio:
1:1
Recommended antifreeze:
High-quality ethylene glycol antifreeze con-
taining corrosion inhibitors for aluminum en-
gines
Coolant quantity:
Radiator capacity (including all routes):
1.80 L (1.90 US qt) (1.58 Imp.qt)
Coolant reservoir capacity (up to the maxi-
mum level mark):
0.30 L (0.32 US qt) (0.26 Imp.qt)
U2C661E0.book Page 28 Thursday, March 16, 2006 10:45 AM
Page 115 of 156

8-31
8
CAUTION:ECB00440Do not twist the sponge material when squeez-ing it.
7. Check the sponge material and replace it if
damaged.
8. Apply a quality foam air filter oil to the sponge
material.NOTE:The sponge material should be wet but not drip-ping.
9. Pull the sponge material over the air filter ele-
ment frame.
10. 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.NOTE:Be sure to connect the breather hose to the air filtercase cover.11. 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.1. Breather hose
U2C661E0.book Page 31 Thursday, March 16, 2006 10:45 AM
Page 118 of 156

8-34
8
EBU23940Adjusting 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:ECB00480The 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 ordamage to the engine.EBU24010Adjusting 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-
tion chart.NOTE:A diagnostic tachometer is needed to make thisadjustment.
1. Start the engine and warm it up.NOTE:The engine is warm when it quickly responds to thethrottle.
2. Remove panel D. (See page 8-8.)
3. Attach the tachometer to the spark plug lead.
1. V-belt case drain plugU2C661E0.book Page 34 Thursday, March 16, 2006 10:45 AM
Page 119 of 156

8-35
8 4. 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 theadjustment.5. Install the panel.
EBU24043Adjusting the throttle cable free play The throttle cable free play should be checked
and, if necessary, adjusted at the intervals speci-
fied in the periodic maintenance and lubrication
chart.
The throttle cable free play should measure 3.0–
5.0 mm (0.12–0.20 in) at the throttle lever. Period-
ically check the throttle cable free play and, if nec-
essary, adjust it as follows.NOTE:The engine idling speed must be checked, and ad-
justed if necessary, before adjusting the throttle ca-ble free play.
1. Loosen the locknut.
2. To increase the throttle cable free play, turn
the adjusting bolt in direction (a). To decrease
the throttle cable free play, turn the adjusting
bolt in direction (b).
1. Throttle stop screwEngine idling speed:
1450–1550 r/min
U2C661E0.book Page 35 Thursday, March 16, 2006 10:45 AM
Page 120 of 156

8-36
83. Tighten the locknut.
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.
EBU24070Adjusting the drive select lever safety
system cable The drive select lever safety system cable stretch-
es with use, which can result in improper function.
Therefore, the safety system cable should be
checked and adjusted at the intervals specified in
the periodic maintenance and lubrication chart.EBU24130Checking the front and 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.EBU24171Front 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.
1. Locknut
2. Throttle cable free play adjusting bolt
3. Throttle cable free playU2C661E0.book Page 36 Thursday, March 16, 2006 10:45 AM
Page 123 of 156

8-39
8
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.EBU24290Changing 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 master cylinders and
calipers as well as the brake hoses replaced at the
intervals listed below or whenever they are dam-
aged or leaking.Oil seals: Replace every two years.Brake hoses: Replace every four years.EBU24390Checking the front brake lever free play The brake lever free play must be checked at the
intervals specified in the periodic maintenance and
lubrication chart. The brake lever should have a
free play of zero mm (zero in) as shown. If the free
play is incorrect, have a Yamaha dealer check the
brake system.
WARNING
EWB02070Operating with improperly serviced or adjust-
ed brakes could cause loss of braking ability,
which could lead to an accident.
After servicing:Make sure the brakes operate smoothly and
that the free play is correct.Make sure the brakes do not drag.Make sure the brakes are not spongy. All air
must be bled from the brake system.
Replacement of brake components requires
professional knowledge. These proceduresshould be performed by a Yamaha dealer.1. Brake lever free play
U2C661E0.book Page 39 Thursday, March 16, 2006 10:45 AM
Page 124 of 156
8-40
8
EBU27140Adjusting the rear brake lever free play
and checking the brake pedal position The brake lever free play must be adjusted and
brake pedal position must be checked and, if nec-
essary, adjusted at the intervals specified in the
periodic maintenance and lubrication chart.NOTE:Always perform this maintenance completely in
the following order whenever adjusting the rear
brake.Before adjusting the brake lever free play and
checking the brake pedal position, check therear brake pads for wear.
Adjusting the brake lever free play
The brake lever free play should measure 0.5–2.0
mm (0.02–0.08 in) as shown. If the free play is in-
correct, adjust it as follows.1. Loosen the locknut.
2. Turn the brake lever free play adjusting bolt in
direction (a) to increase the free play, and in
direction (b) to decrease it.
1. Brake lever free play
U2C661E0.book Page 40 Thursday, March 16, 2006 10:45 AM
Page 126 of 156
8-42
8
Make sure the brakes are not spongy. All air
must be bled from the brake system.
Replacement of brake components requires
professional knowledge. These proceduresshould be performed by a Yamaha dealer.EBU24230Axle boots The axle boots must be checked for damage at the
intervals specified in the periodic maintenance and
lubrication chart. Check the axle boots for tears or
damage. If any damage is found, have them re-
placed by a Yamaha dealer.
EBU24751Brake light switches The operation of the brake light switches must be
checked and, if necessary, adjusted at the inter-
vals specified in the periodic maintenance and lu-
brication chart.
The brake light switch for the brake pedal can be
adjusted as follows, but the other brake light
switches should be adjusted by a Yamaha dealer.
1. Remove panel B. (See page 8-8.)
1. Front axle boot (each side)
1. Rear axle boot (each side)
U2C661E0.book Page 42 Thursday, March 16, 2006 10:45 AM