2008 YAMAHA YFM250R ignition

4-2
1
2
34
5
6
7
8
9
10
11

EBU18061
Handlebar switches
EBU18070
Engine stop switch “ENG. STOP”
Set this switch to “RUN” 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 “OFF”.
EBU18090
Start switch “START”
Push this switch to crank the engine with the start-
er.CAUTION:

ECB00050
See the starting instructions on page 6-1 prior
to starting the engine.
EBU18120
Light switch “LIGHTS”
Set this switch to “LO” to turn on the low beams
and the taillight. Set the switch to “HI” to turn on the
high beams and the taillight. Set the switch to
“OFF” to turn off all the lights.
NOTE:

The headlights and the taillight can be turned on
only when the engine is running.
EBU18280
Throttle lever
Once the engine is running, movement of the throt-
tle lever will increase the engine speed.
Regulate the speed of the ATV by varying the
throttle position. Because the throttle is spring-
loaded, the ATV will decelerate, and the engine will
1. Light switch “LIGHTS”
2. Engine stop switch “ENG. STOP”
3. Start switch “START”
1
2
3

4-4
1
2
34
5
6
7
8
9
10
11

3. Tighten the locknut.
WARNING

EWB00240
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
(0.47 in) or the throttle cable could be dam-
aged. Always make sure the throttle lever free
play is adjusted to 2.0–4.0 mm (0.08–0.16 in).
(See page 8-20.)
EBU18382
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. 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.)
1. Locknut
2. Adjusting screw
3. No more than 12 mm (0.47 in)
31
2
(a)(b)

1. Clutch lever

6-1
1
2
3
4
56
7
8
9
10
11

EBU19880
OPERATION
EBU19900
Read the Owner’s Manual carefully before riding
the ATV.
WARNING

EWB00630
Read 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. If there is a control or func-
tion you do not understand, ask your Yamaha
dealer.
EBU20101
Starting a cold engine
WARNING

EWB00640
Always make sure all control cables work
smoothly before you begin riding in cold
weather. If the control cables are frozen or do
not work smoothly, you could be unable to
control the ATV, which could lead to an acci-
dent or collision.
CAUTION:

ECB00150
See 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 main switch to “ON” and the engine
stop switch to “RUN”.
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.
NOTE:

This 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:

8-43
1
2
3
4
5
6
78
9
10
11
Front

2. Lower the ATV to the ground.
3. Tighten the wheel nuts to the specified
torques.
EBU25720
Troubleshooting
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.
The following troubleshooting chart represents a
quick and easy procedure for checking these vital
systems yourself. However, should your ATV re-
quire any repair, take it to a Yamaha dealer, whose
skilled technicians have the necessary tools, expe-
rience, and know-how to service the ATV properly.
Use only genuine Yamaha replacement parts. Im-
itation parts may look like Yamaha parts, but they
are often inferior, have a shorter service life and
can lead to expensive repair bills.
WARNING
EWB02280
Do not smoke when checking the fuel system.
Fuel can ignite or explode, causing severe inju-
ry or property damage. Make sure there are no
open flames or sparks in the area, including pi-
lot lights from water heaters or furnaces.
1. Arrow mark
Tightening torques:
Front wheel nut:
45 Nm (4.5 m·kgf, 32.5 ft·lbf)
Rear wheel nut:
45 Nm (4.5 m·kgf, 32.5 ft·lbf)

8-44
1
2
3
4
5
6
78
9
10
11

EBU25751
Troubleshooting chart
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 charge the battery if necessary.
DryWet
Open the throttle halfway and operate
the electric starter.

10-4
1
2
3
4
5
6
7
8
910
11
Front suspension:

Type:
Double wishbone
Spring/shock absorber type:
Coil spring/oil damper
Wheel travel:
190 mm (7.5 in)
Rear suspension:
Type:
Swingarm
Spring/shock absorber type:
Coil spring/gas-oil damper
Wheel travel:
200 mm (7.9 in)
Electrical system:
Ignition system:
DC. CDI
Charging system:
AC magneto
Battery:
Model:
YTZ7S
Voltage, capacity:
12 V, 6.0 Ah
Headlight:
Bulb type:
Krypton bulb
Bulb voltage, wattage x quantity:
Headlight:
12 V, 30.0/30.0 W
×
2Tail/brake light:
12 V, 5.0/21.0 W
×
1
Neutral indicator light:
12 V, 1.7 W
×
1

Fuse:
Fuse:
15.0 A