Yamaha YXF10WRAN Owner's Manual page 144

If a spark plug shows signs of electrode ero-
sion and excessive carbon or other deposits,
it should be replaced.
Specified spark plug:
NGK/LMAR8GI-8
Before installing a spark plug, the spark plug
gap should be measured with a wire thick-
ness gauge and, if necessary, adjusted to
specification.
9
1
1. Spark plug gap
Spark plug gap:
0.7–0.8 mm (0.028–0.031 in)
Clean the surface of the spark plug gasket
and its mating surface, and then wipe off any
grime from the spark plug threads.
Tightening torque:
Spark plug:
13 N·m (1.3 kgf·m, 9.6 lb·ft)
TIP
If a torque wrench is not available when in-
stalling the spark plug, a good estimate of the
correct torque is 1/4–1/2 turn past finger tight.
However, the spark plug should be tightened
to the specified torque as soon as possible.
ECB02900
NOTICE
Do not use any tools to remove or install
the spark plug cap, otherwise the ignition
coil coupler may be damaged. The spark
plug cap may be difficult to remove be-
9-30