Yamaha VMX12H Supplementary Service Manual page 328

IGNITION SYSTEM
7-25
I
T OUBLESHOOT N G
The entire ignition system can be checked for
misfire and weak spark by using the Electro
Tester.
1. Warm up the engine so that all of the electri-
cal componentsare a t operatingtemperature.
2.
Connect:
Tester
3. Start the engine, and increase the spark gap
until misfire occurs. (Test a t various
between idle and red line.)
Spark plug lead
Spark plug
Do not run the engine in neutral above 6,000
for more than 1 or
Minimum Spark Gap: 6 mm (0.24 in)
Faulty ignition system operation ( a t the
mum spark gap or smaller)
shooting chart until the source of the problem
is located.
2
seconds.
mini-
Follow the trouble-
+ =