Ignition System; Troubleshooting - Yamaha YZ250 2022 Owner's Service Manual

EAM20142

IGNITION SYSTEM

EAM30278

TROUBLESHOOTING

The ignition system fails to operate (no spark or intermittent spark).
TIP
Before troubleshooting, remove the following part(s):
1. Seat
2. Fuel tank
1. Check the spark plug.
Refer to "CHECKING THE SPARK
PLUG" on page 3-5.
OK
2. Check the ignition spark gap.
Refer to "CHECKING THE IGNI-
TION SPARK GAP" on page 8-8.
NG
3. Check the spark plug cap.
Refer to "CHECKING THE SPARK
PLUG CAP" on page 8-8.
OK
4. Check the ignition coil.
Refer to "CHECKING THE IGNI-
TION COIL" on page 8-8.
OK
5. Check the engine stop switch.
Refer to "CHECKING THE
SWITCHES" on page 8-6.
OK
6. Check the pickup coil.
Refer to "CHECKING THE PICKUP
COIL" on page 8-9.
OK
7. Check the source coil.
Refer to "CHECKING THE
SOURCE COIL" on page 8-9.
OK
8. Check the entire ignition system wir-
ing.
Refer to "WIRING DIAGRAM" on
page 8-1.
OK
Replace the CDI unit.
Re-gap or replace the spark plug.
NG
Ignition system is OK.
OK
Replace the spark plug cap.
NG
Replace the ignition coil.
NG
Replace the engine stop switch.
NG
Replace the pickup coil.
NG
Replace the CDI magneto.
NG
Properly connect or replace the wiring har-
ness.
NG
8-2
IGNITION SYSTEM