Page 93 of 148
8-18
8 4. Remove the engine oil filler cap, and then
wipe the dipstick off with a clean rag.
5. Insert the dipstick into the filler hole (without
screwing it in), and then remove it again to
check the oil level.
TIPThe engine oil should be between the minimumand maximum level marks.
6. 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.
7. Insert the dipstick into the oil filler hole, and
then tighten the engine oil filler cap.
8. Install the panel.
1. Engine oil filler cap
1. Dipstick
2. Maximum level mark
3. Minimum level mark
U3C263E0.book Page 18 Thursday, May 15, 2008 10:44 AM
Page 98 of 148
8-23
83. If the oil is below the brim of the filler hole, add
sufficient oil of the recommended type to raise
it to the correct level.
4. Install the oil filler bolt, and then tighten it to the
specified torque.
To change the final gear oil
1. Place the ATV on a level surface.2. Remove the final gear case guard by remov-
ing the bolts.
3. Place an oil pan under the final gear case to
collect the used oil.
4. Remove the final gear oil filler bolt and the fi-
nal gear oil drain bolt to drain the oil from the
final gear case.
1. Final gear oil
2. Final gear oil filler bolt
3. Correct oil levelTightening torque:
Final gear oil filler bolt:
23 Nm (2.3 m·kgf, 17 ft·lbf)
1. Final gear case guard
2. Bolt
U3C263E0.book Page 23 Thursday, May 15, 2008 10:44 AM
Page 116 of 148

8-41
8Rear brake
TIPTo check the rear brake fluid level, remove cowlingB. (See page 8-9.)
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.EBU24291Changing the brake fluid Have a Yamaha dealer change the brake fluid at
the intervals specified in the TIP after the periodic
maintenance and lubrication chart. In addition,
have the oil seals of the master cylinders and cali-
pers as well as the brake hoses replaced at the in-
tervals listed below or whenever they are damaged
or leaking.Oil seals: Replace every two years.Brake hoses: Replace every four years.
1. Minimum level markRecommended brake fluid:
DOT 4
U3C263E0.book Page 41 Thursday, May 15, 2008 10:44 AM
Page 137 of 148
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 (8.7 in)
Minimum turning radius:
3000 mm (118 in)Weight:With oil and fuel:
250.0 kg (551 lb)Noise and vibration level:Noise level (77/311/EEC):
80.8 dB(A)
Vibration on seat (EN1032, ISO5008):
Will not exceed 0.7 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
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
U3C263E0.book Page 1 Thursday, May 15, 2008 10:44 AM
Page 138 of 148

10-2
10
Engine oil:Type:
SAE 5W-30 or SAE 10W-30 or SAE 10W-40 or SAE
15W-40 or SAE 20W-40 or SAE 20W-50
Recommended engine oil grade:
API service SG type or higher, JASO standard MA
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:
SAE 80 API GL-4 Hypoid gear oil
Quantity:
0.23 L (0.24 US qt, 0.20 Imp.qt)
Differential gear oil:Type:
SAE 80 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 × 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
1020 304050 ˚C
SAE 15W-40
SAE 20W-40SAE 20W-50
SAE 10W-40
SAE 5W-30
SAE 10W-30
U3C263E0.book Page 2 Thursday, May 15, 2008 10:44 AM
Page 140 of 148
10-4
10
Rear wheel:Wheel type:
Panel wheel
Rim size:
12 x 7.5ATFront brake:Type:
Dual disc brake
Operation:
Right hand operation
Recommended fluid:
DOT 4Rear brake:Type:
Single disc brake
Operation:
Left hand and right foot operation
Recommended fluid:
DOT 4Front suspension:Type:
Double wishbone
Spring/shock absorber type:
Coil spring/oil damper
Wheel travel:
160 mm (6.3 in)Rear suspension:Type:
Swingarm
Spring/shock absorber type:
Coil spring/oil damperWheel travel:
180 mm (7.1 in)
Electrical system:Ignition system:
DC. CDI
Charging system:
AC magnetoBattery:Model:
YTX20L-BS
Voltage, capacity:
12 V, 18.0 AhHeadlight:Bulb type:
Krypton bulbBulb voltage, wattage × quantity:Headlight:
12 V, 30.0/30.0 W × 2
Tail/brake light:
12 V, 5.0/21.0 W × 1
Neutral indicator light:
LED
Reverse indicator light:
LED
Coolant temperature warning light:
LED
Park indicator light:
LED
On-Command four-wheel-drive indicator:
LCD
U3C263E0.book Page 4 Thursday, May 15, 2008 10:44 AM