Advance Control (Metro w/o ESA & Spectrum)

Distributor utilizes centrifugal and vacuum advance mechanisms to advance ignition timing relative to engine speed and load.

Centrifugal advance operates in accordance with engine RPM. Beginning at approximately 750 RPM (1 degree), mechanism reaches full advance at approximately 3000 RPM (10 degrees).

Vacuum advance consists of 2 vacuum chambers "A" and "B". Chamber "B" controls idle speed advance from 0-4 degrees. Chamber "A" in conjunction with chamber "B" controls advance at engine RPM above idle, to a maximum of 15 degrees.