Operation Manual

EAU00462
PERIODIC MAINTENANCE AND MINOR REPAIR
To install a spark plug
1. Measure the spark plug gap with a
wire thickness gauge and, if neces-
sary, adjust the gap to specification.
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 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 fin-
ger tight. However, the spark plug should
be tightened to the specified torque as
soon as possible.
4. Install the spark plug cap.
5. Place the spark plug cover in the orig-
inal position.
6-6
6
a. Spark plug gap
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 motorcycle
is ridden normally).
2. Check that all spark plugs installed in
the engine have the same color.
NOTE:
If any spark plug shows a distinctly differ-
ent color, the engine could be defective.
Do not attempt to diagnose such problems
yourself. Instead, have a Yamaha dealer
check the motorcycle.
3. Check each spark plug for electrode
erosion and excessive carbon or oth-
er deposits, and replace it if neces-
sary.
Specified spark plug:
BPR7ES (NGK) or
W22EPR-U (DENSO)
Tightening torque:
Spark plug:
20 Nm (2.0 m·kgf)
Spark plug gap:
0.7-0.8 mm