Yamaha WOLVERINE 2015 Owner's Manual page 148

Inspection
The spark plug is an important engine com-
ponent and is easy to inspect. The condition
of the spark plug can indicate the condition of
the engine.
The ideal color of the porcelain insulator
around the center electrode is a medium-to-
light tan for a vehicle that is being ridden nor-
mally.
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 ex-
cessive, or if carbon and other deposits are
8
excessive, you should replace the spark plug
with the specified plug.
Specified spark plug:
NGK/CPR7EA-9
Measure the spark plug gap with a wire thick-
ness gauge and, if necessary, adjust the gap
to specification.
1
1. Spark plug gap
Spark plug gap:
0.8–0.9 mm (0.031–0.035 in)
Installation
1. Clean the surface of the spark plug gas-
ket and its mating surface, and then wipe
off any grime from the spark plug
threads.
2. Install the spark plug and tighten it to the
specified torque. If a torque wrench is not
available when you are installing the
spark plug, a good estimate of the cor-
8-33