Centrifugal Advance

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


IGNITION TIMING: 7° BTDC (VACUUM HOSE CONNECTED)

IDLE SPEED: 850 rpm

Fig. 7 Disabling vacuum advance:

3. Remove the vacuum hose from the distributor vacuum control unit and plug the hose Fig. 7.

Fig. 10 Centrifugal advance curve:

4. While gradually increasing engine rpm, check changes in ignition timing with a timing light Fig. 10.

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.