
8-24
8
7. Check the oil filler bolt gasket for damage, and
replace it if necessary.
8. Install the oil filler bolt and its gasket, and then tighten the bolt to the specified torque.
9. Check the final gear case for oil leakage. If oil is leaking, check for the cause.
10. Install the engine guard and the final gear case guard by installing the bolts, and then
tightening them to the specified torques.
EBU23426Differential gear oil 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 level must be checked and the oil changed as follows at the in-
tervals specified in the periodic maintenance and
lubrication chart.
To check the differential gear oil level
1. Place the ATV on a level surface.
2. Remove the differential gear oil filler bolt and its gasket, and then check the oil level in the
differential gear case. The oil level should be
at the brim of the filler hole.
Tightening torque:
Final gear oil filler bolt:22 Nm (2.2 m ·kgf, 16 ft ·lbf)
Tightening torques: Engine guard bolt:7 Nm (0.7 m ·kgf, 5.1 ft ·lbf)
Final gear case guard bolt: 7 Nm (0.7 m ·kgf, 5.1 ft ·lbf)
1. Differential gear oil filler bolt
2. Gasket
3. Differential gear oil
4. Correct oil level
1
2
3
4
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8-25
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. Check the gasket for damage, and replace it if necessary.
5. Install the oil filler bolt and its gasket, and then tighten the bolt to the specified torque.
To change the differential gear oil 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, the differential gear oil drain bolt and their gasket
to drain the oil from the differential gear case. 4. Install the drain bolt and its new gasket, and
then tighten the bolt to the specified torque.
5. Refill with the recommended differential gear oil to the brim of the filler hole as shown.
NOTICE: Be sure no foreign material en-
ters the differential gear case.
[ECB00411]
Tightening torque: Differential gear oil filler bolt:23 Nm (2.3 m ·kgf, 17 ft· lbf)
1. Differential gear oil drain bolt
2. GasketTightening torque:
Differential gear oil drain bolt:9.8 Nm (0.98 m ·kgf, 7.1 ft· lbf)
12
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8-26
8
6. Check the oil filler bolt gasket for damage, and replace it if necessary.
7. Install the oil filler bolt and its gasket, and then tighten the bolt to the specified torque. 8. Check the differential gear case for oil leak-
age. If oil is leaking, check for the cause.
EBU23470Coolant The coolant level should be checked before each
ride. In addition, the coolant must be changed at
the intervals specified in the periodic maintenance
and lubrication chart.EBU27126To check the coolant level1. Place the ATV on a level surface.TIPThe coolant level must be checked on a cold en-
gine since the level varies with engine tempera-
ture.2. Check the coolant level in the coolant reser- voir.TIPThe coolant should be between the minimum and
maximum level marks.
1. Differential gear oil filler bolt
2. Gasket
3. Differential gear oil
4. Correct oil levelRecommended differential gear oil:See page 10-1.
Tightening torque: Differential gear oil filler bolt:23 Nm (2.3 m ·kgf, 17 ft ·lbf)
1
2
3
4
U1CT61E0.book Page 26 Wednesday, April 20, 2011 6:36 PM

8-40
8
EBU29841Checking the brake fluid level Before riding, check that the brake fluid is above
the minimum level mark. Check the brake fluid lev-
el with the top of the reservoir level. Replenish the
brake fluid if necessary.
WARNING
EWB02720Improper maintenance can result in loss of
braking ability. Observe these precautions:
Insufficient brake fluid may allow air to enter
the brake system, reducing braking perfor-
mance.Clean the filler cap before removing. Use
only DOT 4 brake fluid from a sealed contain-
er.Use only the specified brake fluid; otherwise,
the rubber seals may deteriorate, causing
leakage.Refill with the same type of brake fluid. Add-
ing a brake fluid other than DOT 4 may result
in a harmful chemical reaction.Be careful that water does not enter the
brake fluid reservoir when refilling. Water
will significantly lower the boiling point of
the fluid and may result in vapor lock.NOTICEECB01160Brake fluid may damage painted surfaces or
plastic parts. Always clean up spilled fluid im-
mediately.As the brake pads wear, it is normal for the brake
fluid level to gradually go down. A low brake fluid
level may indicate worn brake pads and/or brake
system leakage; therefore, be sure to check the
1. Minimum level markSpecified brake fluid:DOT 4
1
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8-41
8brake pads for wear and the brake system for leak-
age. If the brake fluid level goes down suddenly,
have a Yamaha dealer check the cause before fur-
ther riding.
EBU24281Changing 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 brake master cylinder 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.EBU24394Checking 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 no
free play as shown. If there is free play, have a
Yamaha dealer check the brake system.
EBU30342Adjusting the rear brake lever and
brake pedal free play, and the brake
pedal height The rear brake lever and brake pedal free play,
and the brake pedal height must be checked and,
if necessary, adjusted at the intervals specified in
the periodic maintenance and lubrication chart.
Adjusting the brake lever free play
The brake lever free play should measure 10.0 mm
(0.39 in). If the free play is incorrect, adjust it as fol-
lows.1. No brake lever free play
U1CT61E0.book Page 41 Wednesday, April 20, 2011 6:36 PM

10-1
10
EBU25961
SPECIFICATIONS
Dimensions:Overall length:1993 mm (78.5 in)
Overall width: 1093 mm (43.0 in)
Overall height:
1120 mm (44.1 in)
Seat height: 840 mm (33.1 in)
Wheelbase: 1233 mm (48.5 in)
Ground clearance:
245 mm (9.6 in)
Minimum turning radius: 3000 mm (118 in)Weight:With oil and fuel:
YFM450FAPB 287.0 kg (633 lb)
YFM45FGPB (panel wheel model) 281.0 kg (619 lb)
YFM45FGPB (cast wheel model) 284.0 kg (626 lb)
YFM45FGPHB 281.0 kg (619 lb)Noise and vibration level:Noise level (77/311/EEC):YFM45FGPB 78.3 dB(A)
YFM45FGPHB 78.3 dB(A)
Vibration on seat (EN1032, ISO5008): YFM45FGPB 0.6 m/s ²
YFM45FGPHB 0.6 m/s ² Vibration on handlebar (EN1032, ISO5008):
YFM45FGPB Will not exceed 2.5 m/s ²
YFM45FGPHB Will not exceed 2.5 m/s ²
Engine:Engine type:
Liquid cooled 4-stroke, SOHC
Cylinder arrangement: Forward-inclined single cylinder
Displacement:
421 cm ³
Bore × stroke:
84.5 × 75.0 mm (3.33 × 2.95 in)
Compression ratio: 10.00 : 1
Starting system:
Electric starter
Lubrication system: Wet sumpEngine oil:Recommended brand:
YAMALUBE
U1CT61E0.book Page 1 Wednesday, April 20, 2011 6:36 PM

10-2
10
Type:SAE 5W-30, 10W-30, 10W-40, 15W-40, 20W-40 or 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:
Yamaha Friction Modified Shaft Drive Gear Oil
Quantity: 0.38 L (0.40 US qt, 0.33 Imp.qt)
Differential gear oil:Type:Yamaha Friction Modified Shaft Drive Gear Oil or SAE 80 API GL-4 Hypoid gear oil
Quantity: 0.23 L (0.24 US qt, 0.20 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:
YFM450FAPB Unleaded gasoline only
YFM45FGPB Regular unleaded gasoline only
YFM45FGPHB Regular unleaded gasoline only
Fuel tank capacity: 15.0 L (3.96 US gal, 3.30 Imp.gal)
Fuel reserve amount:
4.5 L (1.19 US gal, 0.99 Imp.gal)Carburetor:Type × quantity:
BSR33 x 1Spark plug (s):Manufacturer/model: NGK/DR8EA
Spark plug gap: 0.6 –0.7 mm (0.024 –0.028 in)
0 10 30 50 70 90 110 130 ˚F
–20 –10 0 10 20 30 40 50 ˚CSAE 5W-30
SAE 10W-30
SAE 10W-40
SAE 15W-40
SAE 20W-40SAE 20W-50
U1CT61E0.book Page 2 Wednesday, April 20, 2011 6:36 PM

INDEX
AAccessories and loading ................................................ 6-6
Accessories, auxiliary jack ........................................... 4-23
Air filter element, cleaning ............................................ 8-30
Axle boots .................................................................... 8-46BBattery .......................................................................... 8-51
Brake fluid, changing ................................................... 8-41
Brake fluid level, checking ........................................... 8-40
Brake lever free play, checking the front ...................... 8-41
Brake lever, front .......................................................... 4-13
Brake levers, checking and lubricating ........................ 8-48
Brake light switches ..................................................... 8-47
Brake pads and friction plates, checking ..................... 8-39
Brake pedal and rear brake lever ................................. 4-13
Brake pedal, checking and lubricating ......................... 8-48
Brakes .......................................................................... 8-38
Brakes, front and rear .................................................... 5-3CCables, checking and lubricating ................................. 8-47
Carburetor, adjusting ................................................... 8-36
Carrier, front ................................................................. 4-22
Carrier, rear .................................................................. 4-22
Chassis fasteners .......................................................... 5-7
Cleaning ......................................................................... 9-1
Coolant .................................................................. 5-3, 8-26
Coolant temperature warning light ................................. 4-3
DDifferential gear oil ................................................ 5-3, 8-24
Drive select lever ......................................................... 4-14
Drive select lever and driving in reverse ........................ 6-3
Drive select lever safety system cable, adjusting ........ 8-38
Drive shaft universal joint, lubricating .......................... 8-49EEngine break-in .............................................................. 6-5
Engine, cold start ........................................................... 6-1
Engine idling speed ..................................................... 8-36
Engine oil ....................................................................... 5-3
Engine oil and oil filter cartridge ................................... 8-17
Engine, starting a warm ................................................. 6-3
Engine stop switch ......................................................... 4-7
EPS warning light .......................................................... 4-3FFinal gear oil ......................................................... 5-3, 8-21
Four-wheel-drive/differential gear lock indicator ............ 4-4
Fuel ....................................................................... 4-15, 5-3
Fuel cock ..................................................................... 4-16
Fuel gauge ..................................................................... 4-6
Fuel tank cap ............................................................... 4-14
Fuses, replacing .......................................................... 8-54HHandlebar switches ....................................................... 4-6
Headlight beam, adjusting ........................................... 8-57
Headlight bulb, replacing ............................................. 8-55
High-range indicator light ............................................... 4-2
U1CT61E0.book Page 1 Wednesday, April 20, 2011 6:36 PM