Yamaha RAPTOR 50 Owner's Manual page 87

1. Spark plug wrench
To check the spark plug
1. Check that the porcelain insulator around the
center electrode of the spark plug is a medi-
um-to-light tan (the ideal color when the ATV
is ridden normally).
NOTE:
If the spark plug shows a distinctly different color,
the engine could be operating improperly. Do not
attempt to diagnose such problems yourself. In-
stead, have a Yamaha dealer check the ATV.
2. Check the spark plug for electrode erosion
and excessive carbon or other deposits, and
replace it if necessary.
Specified spark plug:
NGK/CR7HSA
To install the spark plug
1. Measure the spark plug gap with a wire thick-
ness gauge and, if necessary, adjust the gap
1
to specification.
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)
1. Spark plug gap
8-9
1
2
3
4
5
6
7
8
9
10
11