Operation CHARM: Car repair manuals for everyone.

Centrifugal Advance


1. Warm up the engine fully.
2. Make sure that the idling speed and ignition timing are within specifications.


IGNITION TIMING: 6° BTDC

IDLE SPEED: MANUAL 850 rpm AUTOMATIC 750 rpm

Fig. 4 Centrifugal advance curve:





3. Remove the vacuum hose from the distributor vacuum control unit and plug the hose.
4. While gradually increasing engine rpm, check changes in ignition timing with a timing light Fig. 4.

Excessive advance: Governor spring is fatigued (If the governor spring is broken, the initial advance is very quick and high).

Insufficient advance: Governor weight or cam is not operating properly.