light YAMAHA BIG BEAR PRO 400 2003 Owner's Manual

8-37 1. Spark plug cap
1. Capuchon de bougie
1. Tapa de bujía
1. Spark plug wrench
1. Clé à bougie
1. Llave de bujías
EBU00680
Spark plug inspection
Removal
1. Remove the spark plug cap.
2. Use the spark plug wrench in the tool kit to re-
move the spark plug as shown.
Inspection
The spark plug is an important engine component
and is easy to inspect. The condition of the spark
plug can indicate the condition of the engine.
The ideal color on the white insulator around the
center electrode is a medium-to-light tan color for a
ATV that is being ridden normally.
Do not attempt to diagnose such problems your-
self. Instead, take the ATV to a Yamaha dealer.
You should periodically remove and inspect the
spark plug because heat and deposits will cause
the spark plug to slowly break down and erode. If
electrode erosion becomes excessive, or if carbon
and other deposits are excessive, you should re-
place the spark plug with the specified plug.
Specified spark plug:
DR8EA (NGK)
EE.book Page 37 Monday, June 18, 2001 10:18 AM

8-75 1. Rear brake light switch 2. Adjusting nut
1. Contacteur de feu stop sur frein arrière 2.Écrou de réglage
1. Interruptor de la luz de freno trasero 2. Tuerca de ajuste
EBU00834
Adjusting the rear brake light switch
The rear brake light switch, which is activated by
the brake pedal and brake levers, is properly ad-
justed when the brake light comes on just before
braking takes effect. If necessary, adjust the brake
light switch as follows.
Turn the adjusting nut while holding the rear brake
light switch in place. To make the brake light come
on earlier, turn the adjusting nut in direction
a. To
make the brake light come on later, turn the adjust-
ing nut in direction
b.
EE.book Page 75 Monday, June 18, 2001 10:18 AM

8-89 1. Main fuse 2. Spare fuse
1. Fusible principal 2. Fusible de rechange
1. Fusible principal 2. Fusible de repuesto
1. Headlight fuse 2. Ignition fuse
3. Auxiliary DC jack fuse 4. Signal fuse
5. Spare fuse
1. Fusible de phare 2. Fusible d’allumage
3. Fusible de connecteur 4. Fusible de signalisation
pour accessoires
5. Fusible de rechange
1. Fusible del faro 2. Fusible del sistema de encendido
3. Fusible de la toma 4. Fusible señalización
auxiliar de CC
5. Fusible de repuesto
EBU00745*
Fuse replacement
1. The fuse cases are under the seat.
2. If a fuse is blown, turn off the main switch and
the switch of the circuit in question. Then, in-
stall a new fuse of the specified amperage.
Turn on the main switch. If the fuse immedi-
ately blows again, consult a Yamaha dealer.
WARNING
_ Always use a fuse of the specified rating. Nev-
er use any type of material or object in place of
the proper fuse. An improper fuse can cause
damage to the electrical system which could
lead to a fire. _CAUTION:_ To prevent accidental short-circuiting, turn off
the main switch when checking or replacing a
fuse. _
Specified fuses:
Main fuse: 30 A
Headlight fuse: 15 A
Ignition fuse: 10 A
Auxiliary DC jack fuse: 10 A
Signal fuse: 10 A
EE.book Page 89 Monday, June 18, 2001 10:18 AM

8-91 1. Cover
1. Cache
1. Cubierta
1. Bulb holder
1. Douille d’ampoule
1. Portalámparas
EBU00402
Replacing the headlight bulb
If the headlight bulb burns out, replace the bulb as
follows:
1. Remove the cover.
2. Turn the bulb holder counterclockwise and
remove the defective bulb.
WARNING
The headlight bulb is hot when it is on and im-
mediately after it is turned off. Wait for the bulb
to cool before touching or removing it. You can
be burned, or a fire could start if the bulb
touches something flammable.3. Put a new bulb into position and secure it in
place with the bulb holder.
4. Reinstall the cover. Adjust the headlight
beam if necessary.
EE.book Page 91 Monday, June 18, 2001 10:18 AM

8-93 1. Adjusting screw (× 2)
1. Vis de réglage (× 2)
1. Tornillo de ajuste (× 2)
EBU00409
Headlight beam adjustmentCAUTION:
It is advisable to have a Yamaha dealer make
this adjustment.1. Vertical adjustment:
To raise the beam, turn the adjusting screw
clockwise.
To lower the beam, turn the screw counter-
clockwise.
EE.book Page 93 Monday, June 18, 2001 10:18 AM

8-95 1. Storage box 2. Nut (× 2)
1. Compartiment de rangement 2.Écrou (× 2)
1. Caja portaobjetos 2. Tuerca (× 2)
1. Bulb holder 2. Bulb
1. Fixation d’ampoule 2. Ampoule
1. Portabombillas 2. Bombilla
EBU00945
Tail/brake light bulb replacement
1. Open the storage box. (See page 4-37.)
2. Remove the nuts together with washers.
3. Remove the bulb holder (together with the
bulb) by turning it counterclockwise.
4. Remove the defective bulb from the bulb
holder by pushing it inward and turning it
counterclockwise.
5. Install a new bulb in the bulb holder by push-
ing it inward and turning it clockwise.
6. Install the bulb holder (together with the
bulb).
7. Install the washers, and then install the nuts.
EE.book Page 95 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

9-9
5. Tie a plastic bag over the exhaust pipe outlet
to prevent moisture from entering.
6. If storing in a humid or salt-air atmosphere,
coat all exposed metal surfaces with a light
film of oil. Do not apply oil to any rubber parts
or the seat cover.
7. Remove the battery and charge it. Store it in
a dry place and recharge it once a month. Do
not store the battery in an excessively warm
or cold place (less than 0°C or more than
30°C).NOTE:Make any necessary repairs before storing the
machine.
EE.book Page 9 Monday, June 18, 2001 10:18 AM

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 12 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
EE.book Page 6 Monday, June 18, 2001 10:18 AM