General - Cub Crafters CC18-180 Maintenance Manual

CUB CRAFTERS, INC.
CC18-180 MAINTENANCE MANUAL

1. GENERAL

The ignition system on the O-360 engines use two magnetos that generate electricity, which is
distributed via a distributor block to the ignition harness. The ignition harness delivers the
energy generated by the magnetos to the spark plugs via shielded conductors. The spark plugs
then carry the energy from the ignition harness into to the combustion chamber where the spark
ignites the air/fuel mixture.
The ignition wiring is arranged so that the left magneto fires the bottom plugs in the cylinders on
the left side of the engine and the top plugs in the right side. The right magneto fires the top
plugs of the left cylinders and the bottom plugs in the right cylinders (Refer to Figure 74-00-1)
Both magnetos incorporate impulse couplings which delay rotation of the magneto during the
engine starts. This in turn retards the spark until each piston reaches top dead center (T.D.C).
At T.D.C., the coupling spins ahead, generating enough voltage to ignite the fuel/air mixture.
The impulse couplings disengage after the engine starts. Because both magnetos have impulse
couplings, the engine should be started with both magnetos on.
Figure 74-00-1 - Engine Firing Order
(Seen from above)
74-00
Manual number TC10000AMM
Page: 2 Date: 05/20/08