8-11
EBU00286
Spark plug inspection
The spark plug is an important engine
component and is easy to inspect. The
condition of the spark plug can indicate the
condition of the engine.
For example, a very white center electrode
porcelain color could indicate an intake air
leak or carburetion problem for that cylin-
der. Do not attempt to diagnose such prob-
lems yourself.
Instead, take the machine to a Yamaha
dealer. You should periodically remove
and inspect the spark plug because heat
and deposits will cause the spark plug to
slowly break down and erode. If electrode
erosion becomes excessive, you should re-
place the spark plug with one of the proper
type.
Before installing the spark plug, measure
the electrode gap with a feeler gauge and
adjust to specification.
a. Spark plug gap
Standard spark plug:
DR7EA (NGK)
Spark plug gap:
0.6 ~ 0.7 mm (0.024 ~ 0.028 in)
