fuel YAMAHA BIG BEAR PRO 400 2003 User Guide

5-11 1. Fuel level 2. Filler tube
1. Niveau de carburant 2. Tube de remplissage
1. Nivel de combustible 2. Tubo del relleno
CAUTION:_ Use only unleaded gasoline. The use of leaded
gasoline will cause severe damage to the en-
gine internal parts such as valves, piston
rings, exhaust system, etc. _
WARNING
_

Do not overfill the fuel tank. Fuel expands
when it heats up. If the fuel tank is over-
filled, fuel could spill out due to heat from
the engine or the sun.


Be careful not to spill fuel, especially on
the engine or exhaust pipe which can
cause a fire and severe injury. Wipe up any
spilled fuel immediately.


Do not refuel right after the engine has
been running and is still very hot.


Be sure the fuel tank cap is closed secure-
ly.
_
EE.book Page 11 Monday, June 18, 2001 10:18 AM

6-3
EBU00505
Starting a cold engine
WARNING
Always make sure all control cables work
smoothly before you begin riding in cold
weather. If the control cables are frozen or do
not work smoothly, you could be unable to
control the ATV, which could lead to an acci-
dent or collision.1. Set the parking brake.
2. Turn the fuel cock to “ON”.
3. Turn the main switch to “ON” and the engine
stop switch to “”.
4. Shift the transmission into neutral.
EE.book Page 3 Monday, June 18, 2001 10:18 AM

6-27 1. Lock plate
1. Verrou de stationnement
1. Placa de bloqueo
EBU00211
Parking
When parking, stop the engine and shift into neu-
tral. Turn the fuel cock to “OFF” and apply the
parking brake.
EBU00220
Parking on a slope
WARNING
Avoid parking on hills or other inclines. Park-
ing on a hill or other incline could cause the
ATV to roll out of control, increasing the
chance of an accident. If you must park on an
incline, put the machine in low gear, apply the
parking brake, and block the front and rear
wheels with rocks or other objects.
Do not park the ATV at all on hills that are so
steep you could not walk up them easily.1. Bring the machine to a stop by applying the
brakes in low gear.
2. Stop the engine.
3. With the rear brake lever and pedal applied,
apply the parking brake and slowly release
the rear brake pedal.
EE.book Page 27 Monday, June 18, 2001 10:18 AM

8-7
EBL00262PERIODIC 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.EE.book Page 7 Monday, June 18, 2001 10:18 AM

8-53 1. Locknut 2. Adjuster
1. Contre-écrou 2. Dispositif de réglage
1. Contratuerca 2. Ajustador
EBU00303
Valve clearance adjustment
The correct valve clearance changes with use, re-
sulting in improper fuel/air supply or engine noise.
To prevent this, the valve clearance must be ad-
justed regularly. This adjustment however, should
be left to a professional Yamaha service techni-
cian.
EBU00305
Select lever safety system cable adjustment
The select lever safety system cable stretches
with use, resulting in improper function.
To prevent this, the cable must be adjusted regu-
larly. This adjustment, however, should be left to a
Yamaha dealer.
EE.book Page 53 Monday, June 18, 2001 10:18 AM

8-97
EBU00413
Troubleshooting
Although Yamaha machines receive a rigid in-
spection before shipment from the factory, trouble
may occur during operation.
Any problem in the fuel, compression, or ignition
systems can cause poor starting and loss of pow-
er. The troubleshooting chart describes a quick,
easy procedure for making checks. If your ma-
chine requires any repair, take it to a Yamaha
dealer.
The skilled technicians at a Yamaha dealership
have the tools, experience, and know-how to prop-
erly service your machine. Use only genuine
Yamaha parts on your machine. Imitation parts
may look like Yamaha parts, but they are often in-
ferior. Consequently, they have a shorter service
life and can lead to expensive repair bills.
WARNING
Do not smoke when checking the fuel system.
Fuel can ignite or explode, causing severe in-
jury or property damage. Make sure there are
no open flames or sparks in the area, including
pilot lights from water heaters or furnaces.
EE.book Page 97 Monday, June 18, 2001 10:18 AM

8-99
EBU00440Troubleshooting chart1. Fuel
Check if there is fuel
in the fuel tank.There is fuel.Turn the fuel
cock to “OFF”.Remove the fuel pipe
from the fuel cock. Fuel cock
clogged.
Clean fuel
cock. Some fuel.Turn the fuel
cock to “RES”.Restart engine.
No fuel.
Supply fuel
2. Compression
Use electric starter
to see if there is
compression.There is compression.
No compression.
3. Ignition
Remove plug and
check electrodes.WetWipe clean with
dry cloth.
DryAttach plug cap and
ground to chassis.Use the
electric starter.Spark good.Ignition system
normal.
Spark weak.
Adjust plug gap
or replace plug. No spark.
Ask a Yamaha dealer to inspect. 4. Battery
Use electric starter.Engine turns over
quickly.Battery good.
Engine turns over
slowly.
Check fuel
flow. Turn the fuel
cock to “ON”.
Compression normal.Ask a Yamaha dealer to inspect.
Recharge, check
connections.
No fuel.
EE.book Page 99 Monday, June 18, 2001 10:18 AM

9-7
EBU00427
B. STORAGE
Long term storage (60 days or more) of your ma-
chine will require some preventive procedures to
guard against deterioration. After thoroughly
cleaning the machine, prepare for storage as fol-
lows:
1. Fill the fuel tank with fresh fuel and add fuel
stabilizer (if available).NOTE:Use of fuel stabilizer eliminates the need to drain
the fuel system. Consult a Yamaha dealer if the
fuel system is to be drained instead.2. Remove the spark plug, pour about one ta-
blespoon of SAE 10W30 or 20W40 motor oil
in the spark plug hole and reinstall the spark
plug. Ground the spark plug wire and turn the
engine over several times to coat the cylinder
wall with oil.
3. Lubricate all control cables.
4. Block up the frame to raise all wheels off the
ground.
EE.book Page 7 Monday, June 18, 2001 10:18 AM

10-1
EBU00428
1-SPECIFICATIONS
Model YFM400FP/YFM400FW
Dimensions:
Overall length 1,956 mm
Overall width 1,155 mm
Overall height 1,144 mm
Seat height 845 mm
Wheelbase 1,210 mm
Minimum ground clearance 215 mm
Minimum turning radius 3,500 mm
Basic weight:
With oil and full fuel tank 286 kg
Engine:
Engine type Air-cooled 4-stroke, SOHC
Cylinder arrangement Forward-inclined single cylinder
Displacement 386 cm
3
Bore
× stroke 83.0 ×
71.5 mm
Compression ratio 8.6:1
Starting system Electric and recoil starter
Lubrication system Wet sump
EE.book Page 1 Monday, June 18, 2001 10:18 AM

10-4
Fuel:
Type For Europe: Regular unleaded gasoline only
For Australia: Unleaded gasoline only
Fuel tank capacity 13.5 L
Fuel reserve amount 1.3 L
Carburetor:
Type / manufacturer BTM32SH/MIKUNI
Spark plug:
Type (Manufacturer) DR8EA (NGK)
Spark plug gap 0.6 ~ 0.7 mm
Clutch type: Wet, centrifugal automatic
Transmission:
Primary reduction system Spur gear
Primary reduction ratio 76/24 (3.167)
Secondary reduction system Shaft drive
Secondary reduction ratio 24/18
× 33/09 (4.889)
Transmission type Constant mesh 5-speed
Operation Left foot operation, Left hand operationModel YFM400FP/YFM400FW
EE.book Page 4 Monday, June 18, 2001 10:18 AM