Page 308 of 452
8-35 1. Engine oil drain bolt
1. Boulon de vidange de l’huile de moteur
1. Perno de drenaje del aceite de motor
7. 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.
8. Insert the dipstick into the oil filler hole, and
then tighten the oil filler cap.
9. Install the panel.
To change the engine oil (with or without oil fil-
ter cartridge replacement)
1. Remove panel F. (See page 8-31 for panel
removal and installation procedures.)
2. Start the engine, warm it up for several min-
utes, and then turn it off.
3. Place an oil pan under the engine to collect
the used oil, and then remove the engine oil
filler cap.
4. Remove the engine oil drain bolt to drain the
oil from the crankcase.
EE.book Page 35 Wednesday, May 11, 2005 1:21 PM
Page 316 of 452

8-43
‘1. Final gear oil filler bolt
2. Correct oil level
3. Final gear oil
1. Boulon de l’orifice de remplissage du carter de transmission finale
2. Niveau d’huile correct
3. Huile de transmission finale
1. Perno del orificio de llenado de aceite de la transmisión final
2. Nivel de aceite correcto
3. Aceite de la transmisión final
12. Start the engine and warm it up for several
minutes. While warming up, check for oil
leakage. If oil leakage is found, turn the en-
gine off immediately and check for the cause.
13. Turn the engine off, and then check the oil
level and correct it if necessary.
14. Install panel F.
EBU15380
Final gear oil
Checking the final gear oil level
1. Place the ATV on a level surface.
2. Remove the oil filler bolt, and then check the
oil level in the final gear case.NOTE:_ The oil level should be at the brim of the filler hole. _3. 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.CAUTION:_ Be sure no foreign material enters the final
gear case. _
EE.book Page 43 Wednesday, May 11, 2005 1:21 PM
Page 318 of 452
8-45 1. Engine guard 2. Final gear case guard
3. Bolt (× 11)
1. Protège-carter 2. Plaque de protection du carter
3. Boulon (× 11)
1. Protector del motor
2. Protector de la caja de la transmisión final
3. Perno (× 11)
4. Install the oil filler bolt, and then tighten it to
the specified torque.
Changing the final gear oil
1. Remove the engine guard and the final gear
case guard by removing the bolts.
2. Place the ATV on a level surface.
3. Place a container under the final gear case to
collect the used oil. Tightening torque:
Final gear oil filler bolt:
23 Nm (2.3 m·kgf)
EE.book Page 45 Wednesday, May 11, 2005 1:21 PM
Page 324 of 452
8-51 1. Differential gear oil
2. Differential gear oil filler bolt
3. Correct oil level
1. Huile de différentiel
2. Boulon de l’orifice de remplissage de l’huile de différentiel
3. Niveau d’huile correct
1. Aceite de engranajes del diferencial
2. Perno de relleno de aceite de engranajes del diferencial
3. Nivel de aceite correcto
EBU07063
Differential gear oil
Checking the differential gear oil
1. Place the ATV on a level surface.
2. Remove the differential gear oil filler bolt and
check the oil level. It should be up to the brim
of the filler hole. If the level is low, add suffi-
cient oil of the recommended type to raise it
to the specified level.CAUTION:_ Be sure no foreign material enters the differen-
tial gear case. _3. Install the differential gear oil filler bolt, and
then tighten it to the specified torque.
Tightening torque:
Differential gear oil filler bolt:
23 Nm (2.3 m·kgf)
EE.book Page 51 Wednesday, May 11, 2005 1:21 PM
Page 326 of 452
8-53 1. Differential gear oil drain bolt
1. Boulon de vidange de l’huile de différentiel
1. Perno de drenaje de aceite de engranajes del diferencial
Replacing the differential gear oil
1. Place the ATV on a level surface.
2. Place a container under the differential gear
case to collect the used oil.
3. Remove the differential gear oil filler bolt and
differential gear oil drain bolt to drain the oil.
4. Install the differential gear oil drain bolt and
tighten it to the specified torque.
Tightening torque:
Differential gear oil drain bolt:
10 Nm (1.0 m·kgf)
EE.book Page 53 Wednesday, May 11, 2005 1:21 PM
Page 372 of 452
8-99
Refill with the same type of brake fluid. Mixing
fluids may result in a harmful chemical reaction
and lead to poor brake performance.
Be careful that water does not enter the master
cylinder reservoirs when refilling. Water will sig-
nificantly 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 im-
mediately.
Have a Yamaha dealer check the cause if the
brake fluid level goes down.
EE.book Page 99 Wednesday, May 11, 2005 1:21 PM
Page 430 of 452
10-1
EBU00428
SPECIFICATIONS
ModelYFM450FAV
Dimensions:
Overall length 1,993 mm
Overall width 1,093 mm
Overall height 1,120 mm
Seat height 830 mm
Wheelbase 1,233 mm
Ground clearance 245 mm
Minimum turning radius 3,000 mm
Basic weight:
With oil and full fuel tank For Europe 285 kg
For Oceania 289 kg
Noise and vibration level:
Noise level (77/311/EEC) (for Europe) 78.3 dB(A)
Vibration on seat (EN1032, ISO5008) (for Europe) Will not exceed 0.5 m/s
2
Vibration on handlebar (EN1032, ISO5008)
(for Europe)Will not exceed 2.5 m/s
2
Engine:
Engine type Liquid-cooled 4-stroke, SOHC
Cylinder arrangement Forward-inclined single cylinder
Displacement 421.0 cm
3
Bore
× stroke 84.5
× 75.0 mm
Compression ratio 10.0 :1
EE.book Page 1 Wednesday, May 11, 2005 1:21 PM