Perio
d
ic maintenance an
d
a
d
justment
7-10
7
To check the spark plu
g
s
1. Check that the porcelain insulator
around the center electrode on
each spark plug is a medium-to-
light tan (the ideal color when the
vehicle is ridden normally).
2. Check that all spark plugs in-
stalled in the engine have the
same color.
TIP
If any 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.
3. Check each spark plug for elec-
trode erosion and excessive car-
bon or other deposits, and replace
it if necessary.
4. Measure the spark plug gap with a
wire thickness gauge and, if nec-
essary, adjust the gap to specifi-
cation.
To install a spark plu
g
1. Clean the surface of the spark
plug gasket and its mating surfa-
ce, 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.
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
specified torque as soon as possible.
3. Install the spark plug cap.
1. Spark plug wrench
Specifie
d
spark plu
g
:
NGK/CR6HSA
DENSO/U20FSR-U
1. Spark plug gap
Spark plu
g
g
ap:
0.6–0.7 mm (0.024–0.028 in)
Ti
g
htenin
g
torque:
Spark plug:
13 N·m (1.3 kgf·m, 9.4 lb·ft)
U46B78E0.book Page 10 Monday, July 4, 2016 2:29 PM
