Yamaha WR250F(W), Owner'S Service Manual, Page: 826 / 912

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ELEC
IGNITION SYSTEM
EC620000
IGNITION SYSTEM
INSPECTION STEPS
Use the following steps for checking the possibility of the malfunctioning engine being attributable to ignition system failure
and for checking the spark plug which will not spark.
*1 marked: Refer to “FUSE INSPECTION” section in the CHAPTER 3.
*2 marked: Refer to “BATTERY INSPECTION AND CHARGING” section in the CHAPTER 3.
*3 marked: Only when the ignition checker is used.
NOTE:
• Remove the following parts before inspection.
1) Seat
2) Fuel tank
• Use the following special tools in this inspection.
*1 Check fuse.
Replace fuse and check
wire harness.
*2 Check battery. Recharge or replace.
Spark gap test
*3 Clean or replace spark
plug.
Check entire ignition system for
connection.
(couplers, leads and ignition coil)
Repair or replace.
Check engine stop switch. Replace.
Check main switch. Replace.
Check ignition coil. Primary coil Replace.
Secondary coil Replace.
Check AC magneto. Pickup coil Replace.
Check neutral switch. Repair or replace.
Replace CDI unit.
Dynamic spark tester:
YM-34487
Ignition checker:
90890-06754
Pocket tester:
YU-3112-C/
90890-03112
No good
OK
No good
OK
Spark
No spark
No good
OK
No good
OK
No good
OK
No good
OK
No good
No good
OK
No good
OK