Ignition Control System (1200, 616 & 1800)

Consists of a vacuum switch which is located between vacuum control valve and servo diaphragm of throttle opener system; accelerator switch, which is attached to throttle linkage at carburetor; and a retard contact point set in distributor. Vacuum switch is controlled by vacuum from vacuum control valve on deceleration. When vacuum control valve is in operation the vacuum switch closes, thereby retarding ignition. When vacuum control valve is not operating, ignition timing will return to normal advance. When manifold vacuum exceeds 80 mm Hg (3.15 in. Hg) switch opens and timing changes from 2° BTDC to 8° BTDC to improve high speed running. Accelerator switch operates when accelerator is depressed. At idle, accelerator switch closes and retards ignition timing. When accelerator is depressed, switch opens and normal advance occurs.