Yamaha YZF-R15A Owner's Manual page 42

PERIODIC MAINTENANCE AND ADJUSTMENT
2. Remove the spark plug as shown,
with the spark plug wrench includ-
ed in the owner's tool kit.
1. Spark plug wrench
To check the spark plug
1. Check that the porcelain insulator
7
around the center electrode of the
spark plug is a medium-to-light
tan (the ideal color when the vehi-
cle is ridden normally).
TIP
If the spark plug shows a distinctly dif-
ferent color, the engine could be oper-
ating improperly. Do not attempt to
diagnose such problems yourself. In-
stead, have a Yamaha dealer check
the vehicle.
2. Check the spark plug for elec-
trode erosion and excessive car-
bon or other deposits,
replace it if necessary.
Specified spark plug:
NGK/CR8E
3. Measure the spark plug gap with
a wire thickness gauge and, if
necessary, adjust the gap to
specification.
1
ZAUE0032
1. Spark plug gap
7-8
Spark plug gap:
0.7–0.8 mm (0.028–0.031 in)
To install the spark plug
and
1. Clean the surface of the spark
plug gasket and its mating sur-
face, and then wipe off any grime
from the spark plug threads.
2. Install the spark plug with the
spark plug wrench, and then tight-
en it to the specified torque.
Tightening torque:
Spark plug:
12.5 Nm (1.25 m·kgf, 9.2 ft·lbf)
TIP
If a torque wrench is not available when
installing a 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 speci-
fied torque as soon as possible.
3. Install the spark plug cap.