2005 YAMAHA YFZ450 ignition

2-17
WARNING
_

Always turn off the engine when refueling.


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


Do not spill gasoline on the engine or ex-
haust pipe/muffler when refueling. Never
refuel while smoking or in the vicinity of
sparks, open flames, or other sources of
ignition such as the pilot lights of water
heaters and clothes dryers. Gasoline can
catch fire. You could be burned.


When transporting the machine in another
vehicle, be sure it is kept upright and that
the fuel cock is in the “OFF” position. Oth-
erwise, fuel may leak out of the carburetor
or fuel tank.


Gasoline is poisonous. If you should swal-
low some gasoline or inhale a lot of gaso-
line vapor, or get some gasoline in your
eyes, see your doctor immediately. If gaso-
line spills on your skin, wash with soap
and water. If gasoline spills on your cloth-
ing, change your clothes.
_
U5TG61.book Page 17 Friday, April 2, 2004 11:28 AM

4-9 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 parada del motor “ENG. STOP”
3. Interruptor de arranque “START”
EBU11580
Engine stop switch “ENG. STOP”
Make sure that the engine stop switch is in the
“RUN” position before starting the engine. The en-
gine 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”.
U5TG61.book Page 9 Friday, April 2, 2004 11:28 AM

4-15 1. Clutch lever
1. Levier d’embrayage
1. Palanca de embrague
EBU00690
Clutch lever
The clutch lever is located on the left handlebar
and the ignition circuit cut-off system is incorporat-
ed 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 sys-
tem.)
U5TG61.book Page 15 Friday, April 2, 2004 11:28 AM

6-5 1. Fully open 2. Half open
3. Closed a. Starter (choke)
1. Complètement ouvert 2. Mi- ouvert
3. Ferméa. Starter (enrichisseur)
1. Abre completamente 2. Semiabierto
3. Cerrado a. Arrancador (estrangulador)
NOTE:_ This model is equipped with an ignition circuit cut-
off system. The engine can be started under the
following conditions.

When the transmission is in neutral. At this
time the neutral indicator light should come
on. If the light does not come on, ask a
Yamaha dealer to inspect it.


When the clutch is disengaged with the trans-
mission in any position. However, it is recom-
mended to shift into neutral before starting
the engine.
_5. Use the starter (choke) in reference to the fig-
ure:
Position
1: Cold engine start-
ambient temperature below 5 °C.
Position
2: Cold engine start-
ambient temperature at 0 °C – 30°C
and warming up position.
Position
3: Cold engine start-
ambient temperature above 25°C
and warm engine start position.
U5TG61.book Page 5 Friday, April 2, 2004 11:28 AM

8-53 1. Panel 2. Bolt (× 2)
3. Quick fastener screw (× 2) 4. Fuel tank cap
1. Cache 2. Boulon (× 2)
3. Vis à serrage rapide (× 2)
4. Bouchon du réservoir de carburant
1. Panel 2. Perno (× 2)
3. Perno del fijador rápido (× 2)
4. Tapón del depósito de combustible
EBU14142
Spark plug inspection
Removal
1. Remove the seat. (See page 4-27 for seat re-
moval and installation procedures.)
2. Remove the bolts and the quick fastener
screws.
3. Remove the fuel tank cap by turning it coun-
terclockwise.
WARNING
_

Always turn off the engine when removing
the fuel tank cap.


Do not remove the fuel tank cap immedi-
ately after the engine has been running
and is still very hot.


Do not spill gasoline on the engine, ex-
haust pipe or muffler.


Never remove the fuel tank cap while
smoking, or in the vicinity of sparks, open
flames, or other sources of ignition such
as the pilot lights of water heaters and
clothes dryers.
_
U5TG61.book Page 53 Friday, April 2, 2004 11:28 AM

8-61
NOTE:_ If a torque wrench is not available when you are in-
stalling a spark plug, a good estimate of the correct
torque is 1/4 to 1/2 turn past finger tight. Have the
spark plug tightened to the specified torque as
soon as possible. _4. Install the spark plug cap.CAUTION:_ Do not use any tools to remove or install the
spark plug cap, otherwise the ignition coil cou-
pler may be damaged. The spark plug cap may
be difficult to remove because the rubber seal
on the end of the cap fits tightly. To remove the
spark plug cap, simply twist it back and forth
while pulling it out; to install it, twist it back
and forth while pushing it in. _5. Place the fuel tank in the original position,
and then install the bolt.
6. Remove the fuel tank cap by turning it coun-
terclockwise.
U5TG61.book Page 61 Friday, April 2, 2004 11:28 AM

8-127
WARNING
_ Battery electrolyte is poisonous and danger-
ous, causing severe burns, etc. It contains sul-
furic acid. Avoid contact with skin, eyes or
clothing.
Antidote:
EXTERNAL: Flush with water.
INTERNAL: Drink large quantities of water or
milk. Follow with milk of magnesia, beaten egg
or vegetable oil. Call a physician immediately.
EYES: Flush with water for 15 minutes and get
prompt medical attention.
Batteries produce explosive gases. Keep
sparks, flame, cigarettes or other sources of
ignition away. Ventilate when charging or us-
ing in an enclosed space. Always shield your
eyes when working near batteries.
KEEP OUT OF REACH OF CHILDREN. _
U5TG61.book Page 127 Friday, April 2, 2004 11:28 AM

8-143
EBU04130
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.
U5TG61.book Page 143 Friday, April 2, 2004 11:28 AM