Yamaha Drag Star XVS125 Owner's Manual page 39

PERIODIC MAINTENANCE AND MINOR REPAIR
1. Spark plug wrench
2. Remove the
shown, with the spark plug
wrench included in the owner's
tool kit.
6
To check the spark plugs
1
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
installed in the engine have the
same color.
NOTE:
spark plug as
If any spark plug shows a distinctly
different color, the engine could be
defective. Do not attempt to diagnose
such
have a Yamaha dealer check the
motorcycle.
3. Check each spark plug for elec-
trode erosion and excessive car-
bon
replace it if necessary.
Specified spark plug:
that all spark
problems yourself. Instead,
or other deposits,
CR7HSA (NGK)
U22FSR-U (DENSO)
6-8
a
plugs
a. Spark plug gap
To install a spark plug
1. Measure the spark plug gap with
a wire thickness gauge and, if
necessary, adjust the gap to
specification.
Spark plug gap:
0.6–0.7 mm
2. Clean the surface of the spark
plug gasket and its mating sur-
and
face, 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.