Yamaha pw80 - Manual (Page 22)

ADJUSTMENT
A WARNING
The engine, exhaust pipe(s), and muffler(s)
will be very hot after the engine has been
run. Be careful not to touch them or to
allow any clothing item to contact them
during inspection or repair.
SPARK PLU^
Standard spark plug:
BP6HS (NGK) or W20FP
(DENSO)
1. Measure the electrode gap with a wire
thickness gauge.
Adjustment can be made by bending the
side electrode.
Electrode gap:
0.6-0.7 mm (0.024-0.028 in)
When installing the plug, always, clean
the gasket surface and use a new gasket.
Wipe off any grime from the threads and
torque the spark plug properly.
Spark plug torque:
25 Nm (2.5 m-kg, 18 ft lb)
2. The insulator must be a medium-to-light
tan color. If not, check carburetion, igni­
tion timing and gas-oil mixing ratio.
If the porcelain is a very dark brown or
black color, then a plug with a hotter heat
range may be required.
This situation is quite common during the
engine break-in period. However, use the
standard plug. If the insulator tip shows
a very light tan or white color or is actually
pure white or if the electrodes show signs
of melting, then a spark plug with a col­
der heat range is required.
NOTE:______________________________
If a torque wrench is not available when you
are installing a spark plug, a good estimate of
the correct torque is 1 /4 to 1 /2 turns past finger
tight. Have the spark plug torqued to the cor­
rect value as soon as possible with a torque
wrench.
IGNITION TIMING CHECKING
1. Ignition timing is checked with Inductive
Timing Light by observing the position of
the stationary punch mark on the stator
and the punch mark on the rotor.
1. Punch mark 2. Stationary punch mark
^ Using a Inductive Timing Light, check to
see that the stationary punch mark and
punch mark on the flywheel magneto are
aligned.
a. Remove the crankcase cover (L).
b. Connect the timing light to the spark plug
lead.
c. Start the engine and keep it running at the
specified speed. Use a tachometer for
checking.
■10-