2003 YAMAHA BIG BEAR PRO 400 oil level

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

5-13
EBU01234
Engine oil/transfer gear oil
Make sure the engine oil/transfer gear oil is at the
specified level. Add oil as necessary. (See pages
8-13–8-25.)
Recommended oil:
Recommended engine oil classification:
API Service SE, SF, SG type or higher
-20˚ -10˚ 0˚
10˚20˚ 30˚40˚50˚C
10W/30
15W/4020W/4020W/50
10W/40
5W/30
U4SH6A.book Page 13 Thursday, May 30, 2002 1:25 PM

5-17
EBU00495
Final gear oil/Differential gear oil
Make sure the final gear oil/differential gear oil is at
the specified level. Add oil as necessary. (See
pages 8-27–8-35.)
If desired, an SAE 80W90 hypoid gear oil may be
used for all conditions.NOTE:_ GL-4 is a quality and additive rating. GL-5 or GL-6
rated hypoid gear oils may also be used. _
EBU01083
Throttle lever
Check to see that the throttle lever operates cor-
rectly. It must open smoothly and spring back to
the idle position when released. Have a Yamaha
dealer repair as necessary for proper operation.Recommended oil:
SAE 80 API GL-4 Hypoid gear oil
U4SH6A.book Page 17 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

8-13 1. Oil filler cap
1. Bouchon de remplissage d’huile
1. Tapa del orificio de llenado de aceite
1. Dipstick 2. Maximum level mark
3. Minimum level mark
1. Jauge 2. Repère de niveau maximum
3. Repère de niveau minimum
1. Varilla 2. Marca de nivel máximo
3. Marca de nivel minimo
EBU01233
Engine oil
Engine oil level measurement
1. Place the ATV on a level surface.
2. Warm up the engine for several minutes, and
then stop it.
3. Remove the engine oil filler cap and wipe off
the dipstick with a clean rag. Insert the dip-
stick in the filler hole without screwing it in.NOTE:_ Wait a few minutes until the oil level settles before
checking. _4. Remove the dipstick and check the oil level.
5. The oil level should be between the maxi-
mum and minimum level marks. If the engine
oil is below the minimum level mark, add the
specified amount of the specified engine oil to
raise it to the specified level.CAUTION:_ Make sure that no foreign material enters the
crankcase. _
U4SH6A.book Page 13 Thursday, May 30, 2002 1:25 PM

8-15 1. Clamp
1. Bride
1. Mordaza
1. Drain bolt (engine oil) 2. O-ring
3. Compression spring 4. Oil strainer
1. Boulon de vidange (huile de moteur) 2. Joint torique
3. Ressort de compression 4. Crépine à huile
1. Perno de drenaje (aceite del motor) 2. Junta tórica
3. Muelle de compresión 4. Colador de aceite
Engine oil replacement and oil filter cleaning
1. Place the ATV on a level surface.
2. Warm up the engine for several minutes, and
then stop it.
3. Place a container under the engine to collect
the used oil.
4. Remove the clamp by removing the screw.
5. Remove the engine oil filler cap and drain bolt
to drain the oil.CAUTION:_ When removing the drain bolt, the compres-
sion spring, oil strainer and O-ring will fall out.
Take care not to lose these parts. _
U4SH6A.book Page 15 Thursday, May 30, 2002 1:25 PM