Yamaha RD400 Betriebsanleitung Seite 89

result; also, carbon w i l l f o r m on the exposed
threads resulting in combustion Chamber hot
spots and thread damage. Always use a spark
plug w i t h the proper reach.
Spark plug reach: 19.0 m m
Before installing any spark plug, measure the
electrode gap w i t h a wire thickness gauge
and adjust t o specification.
Spark plug gap: 0.6 ~ 0.7 m m
When installing the plug, always clean the gas-
ket surface. Wipe o f f any grime f r o m the
threads and torque the spark plug properly.
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