Magnetos - Cub Crafters CC11-100 Maintenance Manual

CUB CRAFTERS, INC.
CC11-100 MAINTENANCE MANUAL
2

MAGNETOS

The ignition system on the O-200 engine uses two magnetos that generate electricity, which is
distributed via a distributor block to the ignition cables. The ignition cables deliver the energy
generated by the magnetos to the spark plugs via shielded conductors. The spark plugs then
carry the energy from the ignition cables into to the combustion chamber where the spark
ignites the air/fuel mixture.
Dual ignition systems are provided with cables from the right magneto connected to the upper
plugs and cables from the left magneto connected to the lower plugs.
Both magnetos incorporate impulse couplings which delay rotation of the magneto during the
engine starts. The function of the impulse coupling is to hold back the magneto rotor just before
the breaker opening position while the drive gear continues its rotation, thereby retarding the
spark. The second function of the impulse coupling is to release the rotor at approximately
T.D.C., allowing the coupling to spin the rotor rapidly through its neutral position, opening the
breaker and producing a hot spark at cranking speed. The impulse couplings disengage after
the engine starts. Because both magnetos have impulse couplings, the engine should be
started with both magnetos on.
Figure 6.3.18.1: Engine Firing Order (Seen from above)
6.3.18
Manual number SC10000AMM
Date: 04/27/2009 Page: 3