PERIODIC MAINTENANCE AND ADJUSTMENT
7-10
7
3. Remove the spark plug as shown,
with the spark plug wrench includ-
ed in the additional tool kit, which
was handed out separately at the
purchase of the vehicle.
To check the spark plugs
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 installed
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 specifica-
tion.
To install a spark plug
1. Clean the surface of the spark plug
gasket and its mating surface, 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.
1. Spark plug cap
1. Spark plug wrench
1
Specified spark plug:
NGK/LMAR7A-9
1. Spark plug gap
Spark plug gap:
0.8–0.9 mm (0.031–0.035 in)
Tightening torque:
Spark plug:
13 Nm (1.3 m·kgf, 9.4 ft·lbf)
U27D10E0.book Page 10 Thursday, July 22, 2010 1:05 PM
