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Impulse Couplings

The Bendix impulse coupling is a spring-loaded mechanical device that assists engine starting in two ways. First, at low engine cranking speed, the flyweight pawl contacts a stop pin, momentarily stopping the magneto rotation for a set delay (lag angle) and winding the spring within the coupling. At the end of the lag angle setting, trip lugs on the coupling shell pulls the flyweight pawl on the impulse cam assembly away from the stop pin allowing the magneto rotor shaft to snap forward, causing a higher voltage and hotter spark to be produced for improved starting performance. Second, the lag angle hinders the ignition spark from the fixed advance ignition timing of the engine to a firing point more optimal for starting the engine. Listed below are Bendix impulse couplings with their correlating cam assemblies.

S20, S200 Series Bendix Impulse Couplings & Cam Assemblies
Impulse Coupling
Part Number
Cam Assembly
Part Number
10-400301-E 10-400166-2-E
10-400302-E 10-400166-2-E
10-400303-E 10-400166-6-E
10-400304-E 10-400166-6-E
10-400305-E 10-400166-6-E
10-400306-E 10-400166-9-E
10-400307-E 10-400166-4-E
10-400313-E 10-400167-4-E
10-400314-E 10-400167-10-E
10-400315-E 10-400167-10-E
10-400316-E 10-400167-6-E
10-400321-E 10-400167-1-E
S1200 Series Bendix Impulse Couplings & Cam Assemblies 
Impulse Coupling
Part Number
Cam Assembly
Part Number
10-400308-E 10-400166-5-E
10-400309-E 10-400166-5-E
10-400312-E 10-400166-1-E
10-400317-E 10-400167-5-E
10-400318-E 10-400167-8-E
10-400319-E 10-400167-7-E
10-400320-E 10-400167-8-E
10-400327-E 10-400167-2-E