Page 17 of 450

Tire wear limit......................................5-31
OPERATION ...........................................6-1
Starting a cold engine ...........................6-3
Starting a warm engine .........................6-9
Warming up...........................................6-9
Drive select lever operation and
reverse driving ..................................6-11
Engine break-in ...................................6-17
Parking ................................................6-19
Parking on a slope ..............................6-21
Accessories and loading .....................6-23
RIDING YOUR ATV..................................7-1
Getting to know your ATV .....................7-3
Ride with care and good judgement .....7-5
Be careful where you ride ...................7-27
Turning your ATV ................................7-39
Climbing uphill.....................................7-45
Riding downhill ....................................7-55
Crossing a slope .................................7-59
Crossing through shallow water ..........7-63
Riding over rough terrain ....................7-69
Sliding and skidding ............................7-71
What to do if .......................................7-75
What to do ..........................................7-75
67
PERIODIC MAINTENANCE AND
ADJUSTMENT ........................................ 8-1
Owner’s manual and tool kit ................. 8-3
Periodic maintenance/lubrication.......... 8-7
Panel removal and installation............ 8-17
Engine oil and oil filter cartridge ......... 8-33
Final gear oil ....................................... 8-43
Differential gear oil.............................. 8-51
Cooling system ................................... 8-57
Changing the coolant.......................... 8-61
Axle boots ........................................... 8-67
Spark plug inspection ......................... 8-69
Air filter element cleaning ................... 8-75
V-belt cooling duct check hose ........... 8-83
V-belt case drain plug ......................... 8-83
Carburetor adjustment ........................ 8-85
Idle speed adjustment ........................ 8-87
Valve clearance adjustment ............... 8-89
Throttle lever adjustment .................... 8-91
Select lever safety system cable
adjustment ........................................ 8-93
Front brake pad check ........................ 8-93
Rear brake pad check ........................ 8-95
Inspecting the brake fluid level ........... 8-97
Brake fluid replacement .................... 8-101
Front brake lever free play................ 8-103
8
U1D960.book Page 2 Wednesday, June 23, 2004 3:59 PM
Page 56 of 450
3-1
EBU00032
DESCRIPTION AND MACHINE
IDENTIFICATION1. Rear shock absorber
assembly spring preload
adjusting ring
2. Storage compartment
and tool kit
3. Spark plug
4. Rear brake fluid reservoir
5. Front shock absorber
assembly spring preload
adjusting ring
6. Brake pedal
7. V-belt case
8. Radiator cap
9. Fuel cock
10. Air filter case
11. Fuses
12. Tail/brake light
13. Engine oil dipstick
14. Oil filter cartridge15. Coolant reservoir
16. V-belt cooling duct check
hose
17. Rear brake lever
18. Left handlebar switches
19. Starter (choke)
20. Horn switch
21. Drive select lever
22. Speedometer unit
23. Main switch
24. Fuel tank cap
25. Auxiliary DC jack
26. Right handlebar switch
27. Throttle lever
28. Front brake leverNOTE:The machine you have purchased may differ
slightly from those shown in the figures of this
manual.
U1D960.book Page 1 Wednesday, June 23, 2004 3:59 PM
Page 258 of 450
7-65
1. Air filter case check hose
1. Flexible de contrôle du boîtier de filtre à air
1. Manguera de comprobación de la caja del filtro de aire
Test your brakes after leaving the water. Do not
continue to ride your ATV without verifying that
you have regained proper braking ability.CAUTION:_ After riding your ATV in water, be sure to drain
the trapped water by removing the check hose
at the bottom of the air filter case, the V-belt
cooling duct check hose, the drive select lever
box check hose and the storage compartment
check hose. Also, remove the V-belt case drain
plug to drain any water that may have accumu-
lated. Wash the ATV in fresh water if it has
been operated in salt water or muddy condi-
tions. _
U1D960.book Page 65 Wednesday, June 23, 2004 3:59 PM
Page 260 of 450
7-67 1. V-belt cooling duct check hose (left front side of ATV)
1. Flexible de contrôle du conduit de refroidissement de la courroie
trapézoïdale (côté avant gauche du VTT)
1. Manguera de comprobación del conducto de enfriamiento de
la correa trapezoidal (lado delantero izquierdo del ATV)
1. Drive select lever box check hose
1. Flexible de contrôle du boîtier du levier de présélection
1. Manguera de comprobación de la caja de la palanca de
selección de marcha
1. Storage compartment check hose
1. Flexible de contrôle du compartiment de rangement
1. Manguera de comprobación del compartimiento porta objetos
1. V-belt case drain plug
1. Boulon de vidange du carter de courroie trapézoïdale
1. Tapón de drenaje de la caja de la correa trapezoidal
U1D960.book Page 67 Wednesday, June 23, 2004 3:59 PM
Page 281 of 450

8-8
Fuel line*Check fuel hose for cracks or damage.
Replace if necessary.Engine oil
Replace. (Warm engine before draining.)Engine oil filter cartridge
Replace.Engine oil strainer*
Clean.Final gear oil
Check oil level/oil leakage.
Replace every 12 month.Differential gear oil
Front brake*Check operation/fluid leakage. (See NOTE page 8-9.)
Correct if necessary.Rear brake*Check operation/fluid leakage.(See NOTE page 8-9.)
Correct if necessary.Select lever safety system
cable*Check operation.
Adjust if necessary.V-belt*Check operation.
Check for cracks or damage.Wheels*Check balance/damage/runout.
Repair if necessary.Wheel bearing*Check bearing assemblies for looseness/damage.
Replace if damaged.Front and rear
suspension*Check operation.
Correct if necessary.Steering system*Check operation./Replace if damaged.
Check toe-in./Adjust if necessary.Rear upper and lower
knuckle pivots*Lubricate with lithium-soap-based grease.Drive shaft universal
joint*Lubricate with lithium-soap-based grease.Engine mount*
Check for cracks or damage.
ITEM ROUTINEWhichever
comes firstINITIAL EVERY
month136612
km
(mi)320
(200)1,200
(750)2,400
(1,500)2,400
(1,500)4,800
(3,000)
hours 20 75 150 150 300
U1D960.book Page 8 Wednesday, June 23, 2004 3:59 PM
Page 356 of 450
8-83 1. V-belt cooling duct check hose (left front side of ATV)
1. Flexible de contrôle du conduit de refroidissement de la courroie
trapézoïdale (côté avant gauche du VTT)
1. Manguera de comprobación del conducto de enfriamiento de
la correa trapezoidal (lado delantero izquierdo del ATV)
1. V-belt case drain plug
1. Boulon de vidange du carter de courroie trapézoïdale
1. Tapón de drenaje de la caja de la correa trapezoidal
EBU06411
V-belt cooling duct check hose
If dust or water collects in the V-belt cooling duct
check hose, remove the hose and clean it.
EBU08741
V-belt case drain plug
After riding in water deep enough to allow it to en-
ter the V-belt case, remove this plug to drain the
water from the case.NOTE:_ If water drains from the V-belt case after removing
the plug, have a Yamaha dealer inspect the ATV
as the water may affect other engine parts. _
U1D960.book Page 83 Wednesday, June 23, 2004 3:59 PM
Page 431 of 450
10-4
Spark plug:
Type/manufacturer DR8EA / NGK
Spark plug gap 0.6–0.7 mm
Clutch type: Wet, centrifugal automatic
Transmission:
Primary reduction system V-belt
Secondary reduction system Shaft drive
Secondary reduction ratio 39/24
× 24/18
× 33/9 (7.944)
Transmission type V-belt automatic
Operation Left hand operation
Reverse gear 29/17 (1.706)
Sub transmission ratio low 45/16 (2.813)
high 38/23 (1.652)
Chassis:
Frame type Steel tube frame
Caster angle 2.5°
Tr a i l 8 . 5 m m
Tire:
Type Tubeless
Size front AT25
×8 - 12
rear AT25
× 10 - 12 ModelYFM450FA
U1D960.book Page 4 Thursday, June 24, 2004 2:51 PM