1. Check that the porcelain insula-
tor around the center electrode of
the spark plug is a medium-to-
light tan (the ideal color when the
vehicle 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.
Instead, have a Yamaha dealer check
the vehicle.
2. Check the spark plug for electro-
de 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
necessary, adjust the gap to spe-
cification.2. Clean the surface of the spark
plug gasket and its mating surfa-
ce, and then wipe off any grime
from the spark plug threads.
3. Install the spark plug with the
spark plug wrench, and then
tighten it to the specified torque.
NOTE:
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 pos-
sible.
4. Install the spark plug cap.
5. Install the cowling.
EAUM2270
Engine oil
The engine oil level should be chec-
ked before each ride. In addition, the
oil must be changed at the intervals
specified in the periodic maintenance
and lubrication chart and when the
service indicator light comes on.
To check the engine oil level
1. Place the scooter on the centers-
tand.
NOTE:
Make sure that the scooter is positio-
ned straight up when checking the oil
level. A slight tilt to the side can result
in a false reading.
2. Start the engine, warm it up for
several minutes, and then turn it
off.
Tightening torque:
Spark plug:
12.5 Nm (1.25 m·kgf, 9.0 ft·lbf)
Spark plug gap:
0.8-0.9 mm (0.031-0.035 in)
Specified spark plug:
NGK/ CPR 9EA-9
PERIODIC MAINTENANCE AND MINOR REPAIR
6-10
6
1B9-F8199-E2.qxd 13/11/07 12:18 Página 51
