T o remove the spark plug
1. Place the vehicle on the center-
stand .
2. Remove panel* (see page 6-5)
3. Remove the spark plug cap.
4. Remove the spark plug as shown
with the spark plug wrench included
in the owner tool kit.
PERIODIC MAINTENANCE AND MINOR REPAIR
6-9
To check the spark plug
1. Check that the porcelain insulator
around the center electrode of the
spark plug is a medium-to-light tan
(the ideal color when the vehicle is
ridden normally).
TIP :
If the spark plug shows a distinctly dif-
ferent color, the engine could be defec-
tive. Do not attempt to diagnose such
problems yourself.
Instead, have a
Yamaha dealer check the vehicle.
2. Check the spark plug for electrode
erosion and excessive carbon or
other deposits, and replace it if
necessary.
To install the spark plug
1. Measure the spark plug gap with a
wire thickness gauge and, if nec-
essary, adjust the gap to specifica-
tion.
2. Clean the surface of the spark plug
gasket and its mating surface, and
then wipe off any grime from the
spark plug threads.
3. 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 speci-
fied torque as soon as possible.
4. Install the spark plug cap .
Specified spark plug:
NGK CR6HSA / DENSO U20FSR-U
1. Spark plug gap
Spark plug gap:
0. 6–0.7 mm (0.0 23–0.0 27in)
Tightening torque:
Spark plug:
12.5 Nm (1.25 m·kgf, 9.0 ft ·lbf)
5. Install the panel.
6
