2012 YAMAHA YFZ450 ignition

4-3
4
EBU18061Handlebar switches EBU18080Engine stop switch“/”
Set this switch to “” before starting the engine.
The engine stop switch controls the ignition and
stops the engine when it is running. Use this switch
to stop the engine in an emergency situation. The
engine will not start or run when this switch is set
to “” .
EBU18101Start switch “”
Push this switch to crank the engine with the start-
er. See the starting instructions on page 6-1 prior
to starting the engine.EBU18154Light switch “//OFF ”
Set this switch to “” to turn on the low beams
and the taillight. Set the switch to “” to turn on
the high beams and the taillight. Set the switch to
“ OFF ” to turn off all the lights.NOTICEECB00043Do not use the headlights with the engine
turned off for an extended period of time, oth-
erwise the battery may discharge to the point
that the starter motor will not operate properly.
If this should happen, remove the battery and
recharge it. (See page 8-48.)EBU18282Throttle lever Once the engine is running, pushing the throttle le-
ver will increase the engine speed.
1. Light switch “/ /OFF”
2. Engine stop switch “/”
3. Start switch “”
1
23
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4-5
43. Tighten the locknut.
EBU18382Clutch 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. To disengage the
clutch, pull the clutch lever toward the handlebar
grip. To engage the clutch, release the clutch lever.
The clutch lever should be pulled rapidly and re-
leased slowly for smooth clutch operation. (See
page 6-1 for a description of the ignition circuit cut-
off system.)
EBU18411Brake lever The brake lever is located at the right handlebar
grip. To apply the front brake, pull the brake lever
toward the handlebar grip.
1. Locknut
2. Adjusting screw
3. No more than 12 mm (0.47 in)
3 1
2
(a)(b)
1. Clutch lever
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6-1
6
EBU19881
OPERATION
EBU19901Read the Owner’s Manual carefully before riding
the ATV. If there is a control or function you do not
understand, ask your Yamaha dealer.
WARNING
EWB00631Read the Owner ’s Manual carefully to become
familiar with all controls in order to help pre-
vent any loss of control, which could cause an
accident or injury.EBU20184Starting a cold engine NOTICEECB00150See the “Engine break-in ” section on page 6-5
prior to operating the engine for the first time.1. Set the parking brake.
2. Turn the fuel cock to “ON ”.
3. Turn the key to “ON ” and the engine stop
switch to “”. 4. Shift the transmission into neutral. The neutral
indicator light should come on. If the indicator
light does not come on, have a Yamaha deal-
er check the electrical circuit.
TIPThis model is equipped with an ignition circuit cut-
off system. The engine can be started under the
following conditions.
The transmission is in neutral.
The clutch is disengaged with the transmission
in gear. However, it is recommended to shift into
neutral before starting the engine.5. Use the starter (choke) in reference to the fig-ure:
Position (1):
Cold engine start with ambient temperature
below 5 ° C (40 °F).
Position (2):
Cold engine start with ambient temperature
between 0 ° C (30 °F) and 30 ° C (90 °F).
Position (3):
Cold engine start with ambient temperature
above 25 °C (80 °F).
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8-11
8
To remove the spark plug
1. Remove the seat. (See page 4-12.)
2. Remove the bolts and the quick fastener screws shown.
3. Remove the fuel tank cap by turning it coun- terclockwise. WARNING! Never remove the
fuel tank cap while smoking, or in the vi-
cinity of sparks, open flames, or other
sources of ignition such as pilot lights of
water heaters and clothes dryers. Always
turn off the engine before removing the
fuel tank cap. Do not remove the fuel tank
cap immediately after the engine has been
running, as it is still very hot. Do not spill
gasoline on the engine, exhaust pipe or
muffler.
[EWB01871]
4. Pull the panel backward, and then remove the panel.
5. Install the fuel tank cap by turning it clockwise.
6. Remove the bolt, and then lift the rear of the fuel tank while sliding the tank slightly rear-
ward.1. Panel
2. Bolt
3. Quick fastener screw
4. Fuel tank cap
2
4 3 1
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8-12
87. Remove the spark plug cap.
NOTICE: Do not
use any tools to remove or install the
spark plug cap, otherwise the ignition coil
coupler may be damaged. The spark plug
cap may be difficult to remove because the
rubber seal on the end of the cap fits tight-
ly. 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.
[ECB00391]
8. Remove the spark plug as shown, with the spark plug wrench included in the owner ’s tool
kit.
1. Bolt
1
1. Spark plug cap
1
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8-55
8
Front
Rear
3. Elevate the ATV and place a suitable stand
under the frame.
4. Remove the nuts from the wheel.
5. Remove the wheel.
EBU25661Installing a wheel 1. Place the ATV on a level surface.
2. Install the wheel and the nuts.
3. Lower the ATV to the ground.
4. Tighten the wheel nuts to the specified torques.EBU25740Troubleshooting Although Yamaha ATVs receive a thorough in-
spection before shipment from the factory, trouble
may occur during operation. Any problem in the fu-
el, compression, or ignition systems, for example,
can cause poor starting and loss of power.
1. Nut
1. Nut
Tightening torques:Front wheel nut:45 Nm (4.5 m ·kgf, 33 ft ·lbf)
Rear wheel nut: 45 Nm (4.5 m ·kgf, 33 ft ·lbf)
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8-57
8
EBU25784Troubleshooting charts Starting problems or poor engine performance
Check the fuel level in
the fuel tank.1. Fuel
There is enough fuel.There is no fuel.
Check the compression.
Supply fuel.
The engine does not start.
Check the compression.
Operate the electric starter.2. Compression
There is compression.
There is no compression.
Check the ignition. Have a Yamaha dealer
check the ATV.
Remove the spark plug
and check the electrodes.3. Ignition
Wipe off with a dry cloth and correct the
spark plug gap, or replace the spark plug.
Have a Yamaha dealer check the ATV.
The engine does not start.
Have a Yamaha dealer
check the ATV.
The engine does not start.
Check the battery.
Operate the electric starter.4. Battery
The engine turns over
quickly.
The engine turns over
slowly.
The battery is good.Check the battery lead connections,
and have a Yamaha dealer charge
the battery if necessary.
DryWet
Open the throttle halfway and operate
the electric starter.
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10-4
10
Rim size:9 x 8.0ATFront brake:Type:
Disc brake
Operation: Right hand operation
Specified brake fluid: DOT 4Rear brake:Type:Disc brake
Operation: Right foot operation
Specified brake fluid:
DOT 4Front suspension:Type:Double wishbone
Spring/shock absorber type:
Coil spring/oil damper
Wheel travel: 230 mm (9.1 in)Rear suspension:Type:
Swingarm (link suspension)
Spring/shock absorber type: Coil spring/gas-oil damper
Wheel travel: 270 mm (10.6 in)
Electrical system:Ignition system:DC CDI
Charging system:
AC magnetoBattery:Model:GT7B-4
Voltage, capacity:
12 V, 6.5 AhHeadlight:Bulb type:Krypton bulbBulb voltage, wattage × quantity:Headlight:
12 V, 30.0/30.0 W × 2
Tail/brake light: 12 V, 5.0/21.0 W × 1
Neutral indicator light:
12 V, 1.7 W × 1
Coolant temperature warning light: 12 V, 1.7 W × 1Fuses:Main fuse:
15.0 A
U1PD60E0.book Page 4 Monday, June 13, 2011 2:57 PM