Yamaha 2003 YFZ450S, Service Manual

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ELEC
IGNITION SYSTEM
EBS01045
TROUBLESHOOTING
Check:
1. fuse
2. battery
3. spark plug
4. ignition spark gap
5. ignition coil resistance
6. main switch
7. engine stop switch
8. throttle switch
9. carburetor switch
10.pickup coil resistance
11.wiring connections (of the entire ignition
system)
NOTE:
_
• Before troubleshooting, remove the following
part(s):
1. seat
2. fuel tank cover
3. side covers (left and light)
4. fuel tank
5. front fender
• Troubleshoot with the following special
tool(s).
EBS01043
YES
NO
EBS01044
YES NO
EBS01032
YES
NO
The ignition system fails to operate (no
spark or intermittent spark).
Dynamic spark tester
P/N. YM-34487
Ignition checker
90890-06754
Pocket tester
P/N. YU-03112-C, 90890-03112
1. Fuse
• Check the fuse for continuity.
Refer to “CHECKING THE SWITCHES”.
• Is the fuse OK?
Replace the fuse.
2. Battery
• Check the condition of the battery.
Refer to “CHECKING AND CHARGING
THE BATTERY” in chapter 3.
Minimum open-circuit voltage
12.8 V or more at 20 °C (68 °F)
• Is the battery OK?
• Clean the battery
terminals.
• Recharge or
replace the battery.
3. Spark plug
• Check the condition of the spark plug.
• Check the spark plug type.
• Measure the spark plug gap.
Refer to “CHECKING THE SPARK PLUG”
in chapter 3.
Standard spark plug
CR8E (NGK)
Spark plug gap
0.7 ~ 0.8 mm (0.028 ~ 0.031 in)
• Is the spark plug in good condition, is it of
the correct type, and is its gap within spec-
ification?
Re-gap or replace
the spark plug.