2004 YAMAHA BIG BEAR PRO 400 maintenance

EBU00946
1-INTRODUCTION
Congratulations on your purchase of the Yamaha
YFM400FP/YFM400FW. It represents the result of
many years of Yamaha experience in the produc-
tion of fine sporting, touring, and pacesetting rac-
ing machines. With the purchase of this Yamaha,
you can now appreciate the high degree of crafts-
manship and reliability that have made Yamaha a
leader in these fields.
This manual will provide you with a good basic un-
derstanding of the features and operation of this
ATV.
This manual includes important safety in-
formation. It provides information about spe-
cial techniques and skills necessary to ride
your ATV. It also includes basic maintenance and
inspection procedures. If you have any questions
regarding the operation or maintenance of your
ATV, please consult a Yamaha dealer.
U4SH6B.book Page 4 Tuesday, May 27, 2003 4:39 PM

Tires ....................................................5-19
How to measure tire pressure .............5-23
Tire wear limit......................................5-25
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 ................................. 8-41
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 check ........................ 8-55
Rear brake shoe inspection ................ 8-57
Brake fluid level check ........................ 8-57
Brake fluid replacement ...................... 8-61
8
U4SH6B.book Page 2 Tuesday, May 27, 2003 4:39 PM

Front brake lever free play ................. 8-63
Rear brake pedal and
lever adjustment ............................... 8-65
Adjusting the rear brake light switch... 8-73
Clutch adjustment............................... 8-75
Cable inspection and lubrication ........ 8-77
Brake and shift pedal/
brake lever lubrication ...................... 8-77
Wheel removal ................................... 8-79
Wheel installation ............................... 8-79
Battery ................................................ 8-81
Battery maintenance .......................... 8-85
Fuse replacement............................... 8-87
Replacing a headlight bulb ................. 8-91
Headlight beam adjustment................ 8-93
Tail/brake light bulb replacement ....... 8-95
Troubleshooting.................................. 8-97
Troubleshooting chart......................... 8-99
CLEANING AND STORAGE ................... 9-1
A. Cleaning ........................................... 9-1
B. Storage ............................................ 9-7
SPECIFICATIONS ................................. 10-1
CONVERSION TABLE .......................... 11-1
91011U4SH6B.book Page 3 Tuesday, May 27, 2003 4:39 PM

2-5

Never attempt wheelies, jumps, or other stunts.


Always inspect your ATV each time you use it
to make sure it is in safe operating condition.
Always follow the inspection and maintenance
procedures and schedules described in this
manual.


Always keep both hands on the handlebars
and both feet on the footboards of the ATV dur-
ing operation.


Always go slowly and be extra careful when op-
erating on unfamiliar terrain. Always be alert to
changing terrain conditions when operating the
ATV.


Never operate on excessively rough, slippery
or loose terrain until you have learned and
practiced the skills necessary to control the
ATV on such terrain. Always be especially cau-
tious on these kinds of terrain.
U4SH6B.book Page 5 Tuesday, May 27, 2003 4:39 PM

5-4
WARNING
Always inspect your ATV each time you use it to make sure the ATV is in safe operating condition.
Always follow the inspection and maintenance procedures and schedules described in the Own-
er’s Manual. Failure to inspect increases the possibility of an accident or equipment damage.
AVERTISSEMENT
_ Toujours effectuer ces contrôles avant chaque départ afin de s’assurer que le VTT peut être utilisé en toute sécu-
rité. Toujours respecter les procédés et intervalles de contrôle et d’entretien repris dans ce manuel. Omettre ces
contrôles accroît les risques d’accident ou d’endommagement du véhicule. _
ADVERTENCIA
Inspeccionar siempre el ATV cada vez que vaya a utilizarse, para asegurarse de que está en condicio-
nes de funcionar sin peligro. Seguir siempre los procedimientos y programas de inspección y mante-
nimiento descritos en el Manual del Propietario. Si no se inspecciona la máquina, aumenta el riesgo de
accidente o avería.U4SH6B.book Page 4 Tuesday, May 27, 2003 4:39 PM

8-1
EBU00516
1-PERIODIC MAINTENANCE AND
ADJUSTMENTPeriodic inspection, adjustment and lubrication will
keep your machine in the safest and most efficient
condition possible. Safety is an obligation of the
machine owner. The most important points of ma-
chine inspection, adjustment and lubrication are
explained on the following pages.
WARNING
Never service an engine while it is running.
Moving parts can catch clothing or parts of the
body, causing injury. Electrical components
can cause shocks or can start fires. Turn off
the engine when performing maintenance un-
less otherwise specified. Have a Yamaha deal-
er perform service if you are not familiar with
machine service.
U4SH6B.book Page 1 Tuesday, May 27, 2003 4:39 PM

8-3 1. Owner’s manual
2. Low-pressure tire gauge
1. Manuel du propriétaire
2. Manomètre basse pression pour pneus
1. Manual del propietario
2. Manómetro de baja presión
1. Owner’s tool kit
1. Trousse à outils du propriétaire
1. Equipo de herramientas del propietario
EBU00256
Owner’s manual and tool kit
You are recommended to put this owner’s manual
and low-pressure tire gauge in the vinyl bag and
always carry them in the storage box. Put the own-
er’s tool kit in the space under the seat. The ser-
vice information included in this manual is
intended to provide you, the owner, with the nec-
essary information for completing your own pre-
ventive maintenance and minor repairs. The tools
provided in the Owner’s tool kit are sufficient for
this purpose, except that a torque wrench is also
necessary to properly tighten nuts and bolts.NOTE:If you do not have a torque wrench available dur-
ing a service operation requiring one, take your
machine to a Yamaha dealer to check the torque
settings and adjust them as necessary.
U4SH6B.book Page 3 Tuesday, May 27, 2003 4:39 PM

8-7
EBU00262
PERIODIC MAINTENANCE/LUBRICATION
ITEM ROUTINEINITIAL EVERY
1
month3
months6
months6
months1
year
Valves*Check valve clearance.
Adjust if necessary.Spark plugCheck condition.
Adjust gap and clean.
Replace if necessary.Air filter elementClean.
Replace if necessary.Every 20–40 hours
(More often in wet or dusty areas.)
Carburetor*Check starter (choke) operation.
Adjust engine idling speed.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 element
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.U4SH6B.book Page 7 Tuesday, May 27, 2003 4:39 PM