2006 YAMAHA YFZ450 engine

4-5
3. Push the start switch. If the warning light
does not come on while the start switch is
pushed, have a Yamaha dealer check the
electrical circuit.
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8The engine may overheat if the ATV is
overloaded. If this happens, reduce the
load to specification.
8Restart after making sure that the light is
off. Continuous use while the light is on
may cause damage to the engine.
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4-7
1. Light switch “LIGHTS”
2. Engine stop switch “ENG. STOP”
3. Start switch “START”
1. Contacteur d’éclairage “LIGHTS”
2. Coupe-circuit du moteur “ENG. STOP”
3. Contacteur du démarreur “START”
1. Interruptor de luces “LIGHTS”
2. Interruptor de paro del motor “ENG. STOP”
3. Interruptor de arranque “START”
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Handlebar switches
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Light switch “LIGHTS”
Set the switch to the “LO” position to turn on the
low beam and the taillight.
Set the switch to the “HI” position to turn on the
high beam and the taillight.
Set the switch to the “OFF” position to turn off all
the lights.
NOTE:
The headlights and the taillight can be turned on
only when the engine is started.
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Start switch “START”
The starter motor cranks the engine when this
switch is pushed.
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See the starting instructions on page 6-3
prior to starting the engine.
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4-9
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Engine stop switch “ENG. STOP”
Make sure that the engine stop switch is in the
“RUN” position before starting the engine. The
engine stop switch controls ignition and can be
used at all times to stop the engine, especially in
an emergency. The engine will not start or run
when the engine stop switch is turned to “OFF”.1
2
3
1. Light switch “LIGHTS”
2. Engine stop switch “ENG. STOP”
3. Start switch “START”
1. Contacteur d’éclairage “LIGHTS”
2. Coupe-circuit du moteur “ENG. STOP”
3. Contacteur du démarreur “START”
1. Interruptor de luces “LIGHTS”
2. Interruptor de paro del motor “ENG. STOP”
3. Interruptor de arranque “START”
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4-11
1. Throttle lever1. Levier d’accélération1. Palanca del aceleración
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Throttle lever
Once the engine is running, movement of the
throttle lever will increase the engine speed.
Regulate the speed of the machine by varying
the throttle position. Because the throttle is
spring-loaded, the machine will decelerate, and
the engine will return to an idle any time the
hand is removed from the throttle lever.
Before starting the engine, check the throttle to
be sure it is operating smoothly. Make sure it
returns to the idle position as soon as the lever
is released.
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Malfunction of the throttle could make it diffi-
cult to speed up or slow down when you
need to. This could cause an accident.
Check the operation of the throttle lever
before you start the engine. If the throttle
does not work smoothly, check for the
cause. Correct the problem before riding the
ATV or consult a Yamaha dealer.
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4-13
1. Locknut 2. Adjusting screw
a. No more than 12 mm
1. Contre-écrou 2. Vis de réglage
a. Pas plus que 12 mm
1. Contratuerca 2. Tornillo de ajuste
a. No más de 12 mm
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Speed limiter
The speed limiter keeps the throttle from fully
opening, even when the throttle lever is pushed
to the maximum. Turning in the adjusting screw
limits the maximum engine power available and
decreases the maximum speed of the ATV.
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Improper adjustment of the speed limiter and
throttle could cause throttle cable damage or
improper throttle operation. You could lose
control, have an accident or be injured. Do
not turn the adjusting screw out more than
12 mm or the throttle cable could be dam-
aged. Always make sure the throttle lever
free play is adjusted to 2–4 mm. See page
8-79.
5TG-9-62 4 5/12/05 5:18 PM Page 4-13

4-15
1. Clutch lever1. Levier d’embrayage1. Palanca de embrague
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Clutch lever
The clutch lever is located on the left handlebar
and the ignition circuit cut-off system is incorpo-
rated in the clutch lever holder. Pull the clutch
lever to the handlebar to disengage the clutch,
and release the lever to engage the clutch. The
lever should be pulled rapidly and released
slowly for smooth clutch operation. (Refer to
“Starting a cold engine” for a description of the
ignition circuit cut-off system.)
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4-19
1. Parking brake lever (Locked position)1. Levier de frein de stationnement (frein serré)1. Palanca del freno de estacionamiento (posición de bloqueo)
1. Parking brake lever (Unlocked position)
1. Levier de frein de stationnement (frein relâché)1. Palanca del freno de estacionamiento
(posición de desbloqueo)
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Parking brake lever
Use the parking brake when you have to start
the engine or park the machine, especially on a
slope. To apply the parking brake, move the
parking brake lever in direction
a. To release
the parking brake, move the parking brake lever
in direction b.
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8Always set the parking brake before start-
ing the engine. The ATV could start mov-
ing unexpectedly if the parking brake is
not applied. This could cause loss of con-
trol or a collision.
8Always be sure you have released the
parking brake before you begin to ride.
The brake could overheat if you ride the
ATV without releasing the parking brake.
You could lose braking performance
which could cause an accident. You could
also wear out the brakes prematurely.
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4-21
1. Shift pedal1. Pédale de sélection1. Pedal del cambio
1. Fuel tank cap
1. Bouchon de réservoir de carburant1. Tapón del depósito de combustible
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Shift pedal
This machine is equipped with a constant-mesh
5-speed transmission. The shift pedal is located
on the left side of the engine and is used in com-
bination with the clutch when shifting.
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Fuel tank cap
Remove the fuel tank cap by turning it counter-
clockwise.
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