Chrysler 20 and 30 HP Outboard Motors Service Manual OB 3435, Page 62Get this manual
Subsection
ELECTRICALSySTEM
GENERAL
The 20 horsepower outboard motor is available with magneto ignitionmanual start, the 30 horsepower C-D ignitionelectric startIn additionthe C-D ignition has an alternatorthe coil When the cam opens the ignition points, the magnetic field collapses very high voltage (approximately 18,000 volts) is induced in the secondary winding, and is routed to the spark plug via the high tension lead When the ignition points are openself induced voltage remains in the primary windingsThis voltage has no place to go except the condenser which is connected in the primary circuit The condenser absorbs all the voltage creating an unbalanced condition in the systemIn an attempt to distribute itself evenly the voltage races back and forth between the primary coil winding and the condenserThe oscillationspump" the current from the secondary coil windings to the spark plug Depressing the stop