
8-11
8 5. Remove the cowling by removing the bolts.
6. Install the fuel tank cap by turning it clockwise.
To install the cowling
1. Remove the fuel tank cap by turning it coun-
terclockwise.
2. Install the cowling by installing the bolts.
3. Install the fuel tank cap by turning it clockwise.
4. Place the handlebar cover in the original posi-
tion.
5. Pass the fuel tank breather hose through the
hole of the handlebar cover.
6. Install the seat.
1. Bolt
1. Bolt (left side)
1. Bolt (right side)
U3C260E0.book Page 11 Tuesday, August 2, 2005 9:52 AM

8-35
8
EBU24041Adjusting 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) as shown. Periodically
check the throttle cable free play and, if necessary,
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).3. 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.1. Locknut
2. Throttle cable free play adjusting bolt
3. Throttle cable free play
U3C260E0.book Page 35 Tuesday, August 2, 2005 9:52 AM

8-53
8 2. Lower the ATV to the ground.
3. Tighten the wheel nuts to the specified
torques.
EBU25740Troubleshooting Although Yamaha ATVs receive a thorough in-
spection before shipment from the factory, trouble
may occur during operation. Any problem in the fu-
el, compression, or ignition systems, for example,
can cause poor starting and loss of power.
The following troubleshooting charts represent
quick and easy procedures for checking these vital
systems yourself. However, should your ATV re-
quire any repair, take it to a Yamaha dealer, whose
skilled technicians have the necessary tools, expe-
rience, and know-how to service the ATV properly.
Use only genuine Yamaha replacement parts. Im-
itation parts may look like Yamaha parts, but they
are often inferior, have a shorter service life and
can lead to expensive repair bills.
WARNING
EWB02280Do not smoke when checking the fuel system.
Fuel can ignite or explode, causing severe inju-
ry or property damage. Make sure there are no
open flames or sparks in the area, including pi-lot lights from water heaters or furnaces.
1. Tapered nutTightening torques:
Front wheel nut:
55 Nm (5.5 m·kgf, 40 ft·lbf)
Rear wheel nut:
55 Nm (5.5 m·kgf, 40 ft·lbf)
U3C260E0.book Page 53 Tuesday, August 2, 2005 9:52 AM

8-54
8
EBU25781Troubleshooting charts Starting problems or poor engine performance
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 battery lead connections,
and charge the battery if necessary.
DryWet
Open the throttle halfway and operate
the electric starter.
U3C260E0.book Page 54 Tuesday, August 2, 2005 9:52 AM

9-2
9
WARNING
EWB02310Wet brakes may have reduced stopping ability,
increasing the chance of an accident. Test the
brakes after washing. Apply the brakes several
times at slow speeds to let friction dry out thelinings.EBU25932Storage Short-term
Always store your ATV in a cool, dry place and, if
necessary, protect it against dust with a porous
cover.CAUTION:ECB00720Storing the ATV in a poorly ventilated room
or covering it with a tarp while it is still wet,
will allow water and humidity to seep in and
cause rust.To prevent corrosion, avoid damp cellars,
stables (because of the presence of ammo-
nia) and areas where strong chemicals arestored.Long-term
Before storing your ATV for several months:
1. Follow all the instructions in the “Cleaning”
section of this chapter.
2. Turn the fuel cock lever to “OFF”.
3. Drain the carburetor float chamber by loosen-
ing the drain bolt; this will prevent fuel deposits
from building up. Pour the drained fuel into the
fuel tank.
4. Fill up the fuel tank and add fuel stabilizer (if
available) to prevent the fuel from deteriorat-
ing.
5. Perform the following steps to protect the cyl-
inder, piston rings, etc. from corrosion.
a. Remove the spark plug cap and spark
plug.
b. Pour a teaspoonful of engine oil into the
spark plug bore. Specified amount:
7.5 ml of stabilizer to each liter of fuel (or 1 oz
of stabilizer to each gallon of fuel)
U3C260E0.book Page 2 Tuesday, August 2, 2005 9:52 AM

10-1
10
EBU25960
SPECIFICATIONS
Dimensions:Overall length:
1978 mm (77.9 in)
Overall width:
1063 mm (41.9 in)
Overall height:
1095 mm (43.1 in)
Seat height:
840 mm (33.1 in)
Wheelbase:
1233 mm (48.5 in)
Ground clearance:
220 mm (8.66 in)
Minimum turning radius:
3000 mm (118.1 in)Weight:With oil and fuel:
250.0 kg (551 lb)Noise and vibration level:Noise level (77/311/EEC):
79.7 dB(A)
Vibration on seat (EN1032, ISO5008):
Will not exceed 0.5 m/s²
Vibration on handlebar (EN1032, ISO5008):
Will not exceed 2.5 m/s²Engine:Engine type:
Liquid cooled 4-stroke, SOHCCylinder arrangement:
Forward-inclined single cylinder
Displacement:
421.0 cm³ (25.69 cu.in)
Bore × stroke:
84.5 × 75.0 mm (3.33 × 2.95 in)
Compression ratio:
10.00 :1
Starting system:
Electric starter
Lubrication system:
Wet sump
U3C260E0.book Page 1 Tuesday, August 2, 2005 9:52 AM

10-2
10
Engine oil:Type:
SAE5W30 or SAE10W30 or SAE10W40 or SAE15W40
or SAE20W40 or SAE20W50
Recommended engine oil grade:
API service SE, SF, SG type or higher
Engine oil quantity:
Without oil filter cartridge replacement:
2.30 L (2.43 US qt) (2.02 Imp.qt)
With oil filter cartridge replacement:
2.40 L (2.54 US qt) (2.11 Imp.qt)Final gear oil:Type:
SAE80 API GL-4 Hypoid gear oil
Quantity:
0.23 L (0.24 US qt) (0.20 Imp.qt)
Differential gear oil:Type:
SAE80 API GL-4 Hypoid gear oil
Quantity:
0.35 L (0.37 US qt) (0.31 Imp.qt)Cooling system:Coolant reservoir capacity (up to the maximum level mark):
0.25 L (0.26 US qt) (0.22 Imp.qt)
Radiator capacity (including all routes):
1.32 L (1.40 US qt) (1.16 Imp.qt)Air filter:Air filter element:
Wet elementFuel:Recommended fuel:
Regular unleaded gasoline only
Fuel tank capacity:
14.5 L (3.83 US gal) (3.19 Imp.gal)
Fuel reserve amount:
4.5 L (1.19 US gal) (0.99 Imp.gal)Carburetor:Manufacturer:
MIKUNI
Type x quantity:
BSR33 x 1Spark plug (s):Manufacturer/model:
NGK/DR8EA
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)
-20˚ -10˚ 0˚
10˚20˚ 30˚40˚50˚C
10W/30
15W/4020W/4020W/50
10W/40
5W/30
U3C260E0.book Page 2 Tuesday, August 2, 2005 9:52 AM

INDEX
AAccessories and loading ................................................ 6-6
Air filter element, cleaning ............................................ 8-30
Axle boots .................................................................... 8-42BBattery .......................................................................... 8-45
Brake fluid, changing .................................................... 8-39
Brake fluid level, checking ............................................ 8-37
Brake lever free play and brake pedal position (rear),
adjusting and checking .............................................. 8-40
Brake lever free play, checking the front ...................... 8-39
Brake lever, front ............................................................ 4-7
Brake levers, checking and lubricating ......................... 8-43
Brake light switches ..................................................... 8-42
Brake pads, checking the front and rear ...................... 8-36
Brake pedal and rear brake lever ................................... 4-7
Brake pedal, checking and lubricating ......................... 8-44
Brakes, front and rear .................................................... 5-4CCables, checking and lubricating ................................. 8-43
Carburetor, adjusting .................................................... 8-33
Chassis fasteners ........................................................... 5-7
Cleaning ......................................................................... 9-1
Coolant .................................................................. 5-3, 8-25
Coolant temperature warning light ................................. 4-2
Cowlings and panels, removing and installing ............... 8-8DDifferential gear oil ......................................................... 5-3Differential gear oil, changing ....................................... 8-23
Drive select lever ............................................................ 4-8
Drive select lever and driving in reverse ........................ 6-3
Drive select lever safety system cable, adjusting ......... 8-36
Drive shaft universal joint, lubricating ........................... 8-44
EEngine break-in .............................................................. 6-5
Engine, cold start ........................................................... 6-1
Engine idling speed ...................................................... 8-34
Engine oil ....................................................................... 5-3
Engine oil and oil filter cartridge ................................... 8-16
Engine, starting a warm ................................................. 6-3
Engine stop switch ......................................................... 4-4FFinal gear oil .......................................................... 5-3, 8-21
Four-wheel-drive indicator .............................................. 4-2
Fuel ......................................................................... 4-9, 5-3
Fuel cock ...................................................................... 4-10
Fuel tank cap .................................................................. 4-8
Fuses, replacing ........................................................... 8-47HHandlebar switches ........................................................ 4-4
Headlight beam, adjusting ............................................ 8-50
Headlight bulb, replacing .............................................. 8-48IIdentification numbers .................................................. 11-1
Indicator lights and warning light .................................... 4-2
Instruments, lights and switches .................................... 5-7
U3C260E0.book Page 1 Tuesday, August 2, 2005 9:52 AM