Spark Plug Inspection - Yamaha WOLVERINE YFM350FXP Owner's Manual

EBU00286

Spark plug inspection

The spark plug is an important engine compo-
nent 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 cylinder.
Do not attempt to diagnose such problems
yourself.
Instead, take the machine to a Yamaha deal-
er. You should periodically remove and in-
spect 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 replace the
spark plug with one of the proper type.
Standard spark plug:
DR8EA (NGK)
Before installing the spark plug, measure the
electrode gap with a feeler gauge and adjust
to specification.
Spark plug gap:
0.6 ~ 0.7 mm (0.024 ~ 0.028 in)
a. Spark plug gap
When installing the spark plug, always clean
the gasket surface and use a new gasket.
Wipe off any grime from the threads and tight-
en to the specified torque.
Tightening torque:
Spark plug:
17.5 Nm (1.75 m·kg, 12.5 ft·lb)
8-14