2003 YAMAHA BIG BEAR PRO 400 brake fluid

Tires ....................................................5-21
How to measure tire pressure .............5-25
Tire wear limit......................................5-27
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
Reverse lock release wire ...................6-15
Shifting ................................................6-17
To start out and accelerate: ................6-19
To decelerate: .....................................6-21
Engine break-in ...................................6-23
Parking ................................................6-27
Parking on a slope ..............................6-27
Accessories and loading .....................6-29
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 ................................7-41
Climbing uphill.....................................7-47
Riding downhill ....................................7-57
Crossing a slope .................................7-61
67
Crossing through shallow water ......... 7-65
Riding over rough terrain .................... 7-69
Sliding and skidding............................ 7-71
What to do if ... ................................... 7-75
What to do ... ...................................... 7-75
PERIODIC MAINTENANCE AND
ADJUSTMENT ......................................... 8-1
Owner’s manual and tool kit ................. 8-3
Periodic maintenance/lubrication.......... 8-7
Engine oil ............................................ 8-13
Transfer gear oil replacement............. 8-23
Final gear oil ....................................... 8-27
Differential gear oil replacement ......... 8-31
Axle boots ........................................... 8-35
Spark plug inspection ......................... 8-37
Air filter cleaning ................................. 8-43
Carburetor adjustment ........................ 8-49
Idle speed adjustment ........................ 8-51
Valve clearance adjustment ............... 8-53
Select lever safety system
cable adjustment .............................. 8-53
Throttle lever adjustment .................... 8-55
Front brake pad inspection ................. 8-55
Rear brake shoe inspection ................ 8-57
Brake fluid level inspection ................. 8-57
Brake fluid replacement ...................... 8-61
8
U4SH6A.book Page 2 Thursday, May 30, 2002 1:25 PM

5-1
EBU00113
1-PRE-OPERATION CHECKS
Before using this machine, check the following points:
ITEM ROUTINE PAGE
Front brakeCheck operation, free play, fluid level and fluid leakage.
Fill with DOT 4 brake fluid if necessary.5-5–5-7,
8-55–8-75
Rear brakeCheck operation, pedal height and free play.
FuelCheck fuel level.
Fill with fuel if necessary.5-9–5-11
Engine oil/
Transfer gear oilCheck oil level.
Fill with oil if necessary.5-13–5-15,
8-13–8-25
Final gear oil/
Differential gear oilCheck for leakage. 5-17, 8-27–8-35
ThrottleCheck for proper throttle cable operation. 5-17, 8-55
Wheels and tiresCheck tire pressure, wear and damage.5-21–5-27,
8-81–8-83
Fittings and FastenersCheck all fittings and fasteners. 5-19
LightsCheck for proper operation. 5-19, 8-91–8-95
Axle bootsCheck operation. 8-35
U4SH6A.book Page 1 Thursday, May 30, 2002 1:25 PM

5-5
EBU01091
Front and rear brakes
Brake levers and brake pedal
Check for correct free play in the brake levers and
brake pedal. If the free play is incorrect, adjust it.
(See pages 8-63–8-73.)
Check operation of the levers and pedal. They
should move smoothly and there should be a firm
feeling when the brake is applied. If not, have a
Yamaha dealer inspect the brake system.
Brake fluid level (front brake)
Check the brake fluid level. Add fluid if necessary.
(See pages 8-57–8-59.)
Recommended brake fluid: DOT 4
U4SH6A.book Page 5 Thursday, May 30, 2002 1:25 PM

5-7
Brake fluid leakage (front brake)
Check to see if any brake fluid is leaking out of the
hose, joint or brake fluid reservoir of the front
brake. Apply the brake firmly for one minute. If the
lever moves slowly inward, there may be a leak in
the brake system. If there is any leakage, the
brake system should be inspected by a Yamaha
dealer.
Brake operation
Test the brakes at slow speed after starting out to
make sure they are working properly. If the brakes
do not provide proper braking performance, in-
spect the brakes for wear. (See pages 8-55–8-57.)
WARNING
_ Always check the brakes at the start of every
ride. Do not ride the ATV if you find any prob-
lem with the brakes or you could lose braking
ability, which could lead to an accident. If a
problem cannot be corrected by the adjust-
ment procedures provided in this manual,
have a Yamaha dealer check for the cause. _
U4SH6A.book Page 7 Thursday, May 30, 2002 1:25 PM

8-7
EBU00262PERIODIC MAINTENANCE/LUBRICATION
ITEM ROUTINEINITIAL EVERY
1
month3
months6
months6
months1
year
Valves*•Check valve clearance.
•Adjust if necessary.Spark plug•Check condition.
•Adjust gap and clean.
•Replace if necessary.Air filter•Clean.
•Replace if necessary.Every 20–40 hours
(More often in wet or dusty areas.)
Carburetor*•Check idle speed/starter operation.
•Adjust if necessary.Crankcase breather
system*•Check breather hose for cracks or damage.
•Replace if necessary.Exhaust system*•Check for leakage.
•Retighten if necessary.
•Replace gasket(s) if necessary.Fuel line*•Check fuel hose for cracks or damage.
•Replace if necessary.Engine oil
•Replace (Warm engine before draining).Transfer gear oil
Engine oil filter
•Replace.Engine oil strainer
•Clean.Final gear oil
•Check oil level/oil leakage.
•Replace every 12 months.Differential gear oil
Front brake*•Check operation/fluid leakage/see NOTE page 8-8.
•Correct if necessary.Rear brake*•Check operation.
•Adjust if necessary.Clutch*•Check operation.
•Adjust if necessary.U4SH6A.book Page 7 Thursday, May 30, 2002 1:25 PM

8-8 * It is recommended that these items be serviced by a Yamaha dealer.
NOTE:

Recommended brake fluid: DOT 4


Brake fluid replacement:
1. When disassembling the master cylinder or caliper cylinder, replace the brake fluid. Normally check
the brake fluid level and add fluid as required.
2. On the inner parts of the master cylinder and caliper cylinder, replace the oil seals every two years.
3. Replace the brake hoses every four years, or if cracked or damaged.
Drive select lever
safety system*•Check operation.
•Adjust if necessary.Wheels*•Check balance/damage/runout.
•Repair if necessary.Wheel bearing*•Check bearing assemblies for looseness/damage.
•Replace if damaged.Steering system*•Check operation.
•Replace if damaged.
•Check toe-in.
•Adjust if necessary.Axle boots*•Check condition.
•Replace if damaged.Fittings and Fasteners*•Check all chassis fittings and fasteners.
•Correct if necessary.
ITEM ROUTINEINITIAL EVERY
1
month3
months6
months6
months1
year
U4SH6A.book Page 8 Thursday, May 30, 2002 1:25 PM

8-57 1. Wear indicator 2. Wear limit
1. Indicateur d’usure 2. Limite d’usure
1. Indicador de desgaste 2. Límite de desgaste
1. Minimum level mark “LOWER”
1. Repère de niveau minimum “LOWER”
1. Marca de nivel mínimo “LOWER”
EBU00313
Rear brake shoe inspection
A wear indicator is provided on the rear brake.
This indicator allows checking of brake shoe wear
without disassembling the brake.
Apply the rear brake and check the position of the
indicator. If the indicator reaches the wear limit
line, ask a Yamaha dealer to replace shoes as a
set.
EBU00755
Brake fluid level inspection
Insufficient brake fluid may let air enter the brake
system, possibly causing the brakes to become in-
effective.
Before riding, check that the brake fluid is above
the lower level and replenish when necessary.
Observe these precautions:
1. When checking the fluid level, make sure the
top of the master cylinder is level by turning
the handlebars.
2. Use only the designated quality brake fluid.
Otherwise, the rubber seals may deteriorate,
causing leakage and poor brake perfor-
mance.
U4SH6A.book Page 57 Thursday, May 30, 2002 1:25 PM

8-59
3. Refill with the same type of brake fluid. Mixing
fluids may result in a harmful chemical reac-
tion and lead to poor brake performance.
4. Be careful that water does not enter the mas-
ter cylinder when refilling. Water will signifi-
cantly lower the boiling point of the fluid and
may result in vapor lock.
5. Brake fluid may deteriorate painted surfaces
or plastic parts. Always clean up spilled fluid
immediately.
6. Have a Yamaha dealer check the cause if the
brake fluid level goes down. Recommended brake fluid: DOT 4
U4SH6A.book Page 59 Thursday, May 30, 2002 1:25 PM