Ignition System - Yamaha YZ450FT Owner's Service Manual

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.
Spark gap test
No spark
Check entire ignition
system for connection.
(couplers, leads and
ignition coil)
OK
Check "ENGINE STOP"
button.
OK
Check ignition coil.
OK
Check CDI magneto.
OK
Check neutral switch.
OK
Replace CDI unit.
*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.
Dynamic spark tester:
YM-34487
Ignition checker:
90890-06754
IGNITION SYSTEM
Spark
No good
No good
No good
Primary coil
No good
Secondary coil
No good
Pick-up coil
No good
Source coil
No good
6 - 3
ELEC
*Clean or replace
spark plug.
Repair or replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Repair or replace.
Pocket tester:
YU-3112-C/90890-03112
– +