2003 YAMAHA BIG BEAR PRO 400 wheel

8-55 1. Adjusting bolt 2. Locknut a. Free play
1. Bouchon de réglage 2. Contre-écrou a. Jeu
1. Perno de ajuste 2. Contratuerca a. Juego libre
1. Brake pad a. Wear limit: 1 mm
1. Plaquette de frein a. Limite d’usure: 1 mm
1. Pastillas del freno a. Límite de desgaste: 1 mm
EBU00307
Throttle lever adjustmentNOTE:Adjust the engine idling speed before adjusting the
throttle lever free play.1. Loosen the locknut.
2. Turn the adjusting bolt until the throttle lever
free play is 3–5 mm.
3. Tighten the locknut.
EBU00312
Front brake pad inspection
Inspect the brake pads for damage and wear. If
the thickness is less than the specified value, have
a Yamaha dealer replace the pads.NOTE:The wheels need to be removed to inspect the
brake pads. See page 8-81 for removal proce-
dures.
U4SH6A.book Page 55 Thursday, May 30, 2002 1:25 PM

8-81
1. Arrow mark
1. Flèche
1. Marca en forma de flecha
EBU01112
Wheel removal
1. Loosen the wheel nuts.
2. Elevate the ATV and place a suitable stand
under the frame.
3. Remove the nuts from the wheel.
4. Remove the wheel.
EBU01121
Wheel installation
1. Install the wheel and the nuts.NOTE:_

Tapered nuts are used for both the front and
rear wheels. Install the nut with its tapered
side towards the wheel.


The arrow mark on the tire must point to-
ward the rotating direction of the wheel.
_
U4SH6A.book Page 81 Thursday, May 30, 2002 1:25 PM

8-83 1. Tapered nut
1.Écrou conique
1. Tuerca cónica
2. Lower the ATV so that the wheel is on the
ground.
3. Tighten the wheel nuts to the specified
torque.
EBU00381
Battery
This machine is equipped with a sealed-type bat-
tery. Therefore it is not necessary to check the
electrolyte or add distilled water in the battery. If
the battery seems to have discharged, consult a
Yamaha dealer.CAUTION:
Do not try to remove the sealing caps of the
battery cells. You may damage the battery.Wheel nut torque:
Front: 55 Nm (5.5 m·kgf)
Rear: 55 Nm (5.5 m·kgf)
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9-1
EBU00420
1-CLEANING AND STORAGE
A. CLEANING
Frequent, thorough cleaning of your machine will
not only enhance its appearance but will improve
its general performance and extend the useful life
of many components.
1. Before cleaning the machine:
a. Block off the end of the exhaust pipe to pre-
vent water entry. A plastic bag and strong
rubber band may be used.
b. Make sure the spark plug and all filler caps
are properly installed.
2. If the engine case is excessively greasy, ap-
ply degreaser with a paint brush. Do not ap-
ply degreaser to the wheel axles.
3. Rinse the dirt and degreaser off with a garden
hose. Use only enough pressure to do the
job.
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9-3
CAUTION:
Excessive water pressure may cause water
seepage and deterioration of wheel bearings,
brakes, transmission seals and electrical de-
vices. Many expensive repair bills have result-
ed from improper high pressure detergent
applications such as those available in coin-
operated car washers.4. Once the majority of the dirt has been hosed
off, wash all surfaces with warm water and
mild, detergent-type soap. An old toothbrush
or bottle brush is handy for hard-to-get-at
places.
5. Rinse the machine off immediately with clean
water and dry all surfaces with a chamois,
clean towel or soft absorbent cloth.
6. Clean the seat with a vinyl upholstery cleaner
to keep the cover pliable and glossy.
U4SH6A.book Page 3 Thursday, May 30, 2002 1:25 PM

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.
U4SH6A.book Page 7 Thursday, May 30, 2002 1:25 PM

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
U4SH6A.book Page 1 Thursday, May 30, 2002 1:25 PM

10-6
Suspension:
Front suspension Double wishbone
Rear suspension Swingarm (monocross)
Shock absorber:
Front shock absorber Coil spring / Oil damper
Rear shock absorber Coil spring / Oil damper
Wheel travel:
Front wheel travel 100 mm
Rear wheel travel 110 mm
Electrical:
Ignition system D.C. C.D.I.
Generator system A.C. magneto
Battery type YTX 20L-BS
Battery voltage, capacity 12 V, 18 AH
Headlight type: Bulb type
Bulb voltage, wattage
× quantity:
Headlight 12 V, 30 W / 30 W
× 2
Tail / brake light 12 V, 5 W / 21 W × 1
Meter light 14 V, 3 W
× 1
Indicator light:
Neutral 12 V, 1.7 W
× 1
Reverse 12 V, 1.7 W × 1
Oil temperature 12 V, 1.7 W
× 1 Model YFM400FP/YFM400FW
U4SH6A.book Page 6 Thursday, May 30, 2002 1:25 PM