Page 17 of 422

How to measure tire pressure .............5-27
Tire wear limit......................................5-29
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............ 8-15
Engine oil and oil filter cartridge ......... 8-29
Final gear oil ....................................... 8-39
Differential gear oil replacement ......... 8-45
Cooling system ................................... 8-51
Changing the coolant.......................... 8-55
Axle boots ........................................... 8-61
Spark plug inspection ......................... 8-63
Air filter element cleaning ................... 8-69
V-belt cooling duct check hose ........... 8-77
V-belt case drain plug ......................... 8-77
Carburetor adjustment ........................ 8-79
Idle speed adjustment ........................ 8-81
Valve clearance adjustment ............... 8-83
Throttle lever adjustment .................... 8-85
Front brake pad check ........................ 8-87
Rear brake shoe inspection ................ 8-87
Brake fluid level check ........................ 8-89
Brake fluid replacement ...................... 8-93
Front brake lever free play.................. 8-95
8
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Page 54 of 422
3-1
EBU00032
DESCRIPTION AND MACHINE
IDENTIFICATION1. Rear shock absorber
assembly spring preload
adjusting ring
2. Storage box and tool kit
3. Spark plug
4. Front shock absorber
assembly spring preload
adjusting ring
5. Brake pedal
6. V-belt case
7. Radiator cap
8. Fuel cock
9. Air filter case
10. Fuses
11. Tail/brake light
12. Front shock absorber
assembly spring preload
adjusting ring
13. V-belt cooling duct check
hose14. Coolant reservoir
15. Oil filter cartridge
16. Engine oil dipstick
17. Rear brake lever
18. Left handlebar switches
19. Starter (choke)
20. Horn switch
21. Drive select lever
22. Speedometer
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.
U5TE61.book Page 1 Tuesday, May 6, 2003 4:40 PM
Page 238 of 422
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 and the drive select
lever box check hose. Also, remove the V-belt
case drain plug to drain any water that may
have accumulated. Wash the ATV in fresh wa-
ter if it has been operated in salt water or mud-
dy conditions. _
U5TE61.book Page 65 Tuesday, May 6, 2003 4:40 PM
Page 240 of 422
7-67 1. V-belt cooling duct check hose
1. Flexible de contrôle du conduit de refroidissement de la courroie
trapézoïdale
1. Manguera de comprobación del conducto de enfriamiento de
la correa trapezoidal
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. 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
U5TE61.book Page 67 Tuesday, May 6, 2003 4:40 PM
Page 261 of 422

8-8
* Since these items require special tools, data and technical skills, have a Yamaha dealer perform the service.NOTE:
Recommended brake fluid: DOT 4
Brake fluid replacement:
When disassembling the master cylinder or caliper, replace the brake fluid. Normally check the
brake fluid level and add fluid as required.
On the inner parts of the master cylinder and caliper, replace the oil seals every two years.
Replace the brake hoses every four years, or if cracked or damaged.
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.Drive shaft universal
joint*Lubricate.Axle boots*Check operation.
Replace if damaged.Fittings and fasteners*Check all chassis fittings and fasteners.
Correct if necessary.Lights and switches*Check operation.
Adjust headlight beams.
ITEM ROUTINEINITIAL EVERY
1
month3
months6
months6
months1
year
U5TE61.book Page 8 Tuesday, May 6, 2003 4:40 PM
Page 330 of 422
8-77 1. V-belt cooling duct check hose
1. Flexible de contrôle du conduit de refroidissement de la courroie
trapézoïdale
1. Manguera de comprobación del conducto de enfriamiento de
la correa trapezoidal
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. _
U5TE61.book Page 77 Tuesday, May 6, 2003 4:40 PM
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10-4
Transmission:
Primary reduction system V-belt
Secondary reduction system Spur gear
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)
Forward gear 38/23 (1.652)
Chassis:
Frame type Steel tube frame
Caster angle 4°
Trail 21 mm
Tire:
Type Tubeless
Size front AT25
×8 - 12
rear AT25
× 10 - 12
Brake:
Front brake type Dual disc brake
operation Right hand operation
Rear brake type Drum brake
operation Left hand and right foot operation Model YFM400FA
U5TE61.book Page 4 Tuesday, May 6, 2003 4:40 PM