Checking The Spark Plug - Yamaha Xenter HW151 Owner's Manual

PERIODIC MAINTENANCE AND ADJUSTMENT

Checking the spark plug

The spark plug is an important engine
component, which is easy to check.
1
Since heat and deposits will cause
any spark plug to slowly erode, the
spark plug should be removed and
2
checked in accordance with the pe-
riodic maintenance and lubrication
3
chart. In addition, the condition of the
spark plug can reveal the condition of
4 the engine.
To remove the spark plug
5
1. Place the vehicle on the center-
stand.
6
2. Remove panel C. (See page 6-8.)
3. Remove the spark plug cap.
4. R e m o v e t h e s p a r k p l u g a s
7
s h o w n , w i t h t h e s p a r k p l u g
wrench included in the owner's
8
tool kit.
9
EAUT1835
1
1. Spark plug wrench
To check the spark plug
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).
TIP
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 elec-
Specifi ed spark plug:
To install the spark plug
1. Measure the spark plug gap with
Spark plug gap:
2. Clean the surface of the spark
3. Install the spark plug with the
Tightening torque:
6-9
trode erosion and excessive
carbon or other deposits, and re-
place it if necessary.
CPR9EA-9 (NGK)
a wire thickness gauge and, if
necessary, adjust the gap to
specifi cation.
0.8 ~ 0.9 mm (0.031 ~ 0.035 in)
plug gasket and its mating sur-
face, and then wipe off any grime
from the spark plug threads.
spark plug wrench, and then
tighten it to the specifi ed torque.
Spark plug:
13 Nm (1.3 m·kgf, 9.4 ft·lbf)
EAU1722A