1.1 Liter Engine
Vacuum advance unit is connected to carburetor vacuum port. Vacuum retard unit is connected to intake manifold balance tube. At engine idle, high manifold vacuum acts on retard diaphragm and assists spring in advance unit to push rod and breaker plate 10° ATDC. When carburetor throttle valves are opened, intake manifold vacuum drops and carburetor venturi vacuum rises causing an immediate action on advance diaphragm. Retard diaphragm follows because of drop in intake manifold vacuum. Vacuum advance travel is not affected by retard mechanism. During periods of deceleration, vacuum retard diaphragm will effect a 10° spark retard.