Yamaha XVS650, Owner'S Manual

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PERIODIC MAINTENANCE AND MINOR REPAIR
6-10
6
NOTE:
@
If any 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 motorcycle.
@
3. Check each spark plug for elec-
trode erosion and excessive car-
bon or other deposits, and replace
it if necessary.
To install a 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 sur-
face, 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.
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 speci-
fied torque as soon as possible.
@
4. Install the spark plug cap.
Specified spark plug:
DPR7EA-9 (NGK) or
X22EPR-U9 (DENSO)
a. Spark plug gap
Spark plug gap:
0.8–0.9 mm (0.03–0.04 in)
Tightening torque:
Spark plug:
18 Nm (1.8 m·kgf, 13 ft·lb)