Yamaha PZ50FXW Owner's Manual page 65

Spark plug reach a: 19.0 mm (0.75 in)
Before installing any spark plug, measure the electrode
gap with a wire thickness gauge and adjust to specifica-
tion.
Spark plug gap b: 0.6–0.7 mm (0.024–0.028 in)
When installing the spark plug, always clean the gasket
surface. Wipe off any grime from the threads and tighten
the spark plug to the specified torque.
Spark plug tightening torque:
12.5 Nm (1.25 m·kgf, 9 ft·lb)
CAUTION :
@
Make sure that the spark plug caps are securely
installed. Otherwise the spark plug caps could be
damaged due to engine vibration.
@
8-10