Yamaha TT-R90 Manuel D'atelier Du Proprietaire page 316

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
Check entire ignition
system for connection.
Check main switch.
(TT-R90E only)
Check "ENGINE STOP"
switch.
Check ignition coil.
Check CDI magneto.
Replace CDI unit.
NOTE:
Remove the following parts before inspection.
G
1) Seat
2) Fuel tank
Use the following special tools in this inspection.
G
Dynamic spark tester:
YM-34487
Ignition checker:
90890-06754
No Spark
OK
OK
OK
Primary coil
Secondary coil
OK
Pickup coil
Source coil
OK
IGNITION SYSTEM
Spark
No good
No good
No good
No good
No good
No good
No good
Pocket tester:
YU-3112-C/90890-03112
6 - 3
– +
ELEC
Clean or replace
spark plug.
Repair or replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.