1997+ Mercury 35/40HP 2 Cylinder Outboards Service Manual PN 90-826148R2, Page 63Get this manual
Theory of Operation This outboard ignition system is alternatordriven (distributorless) capacitor discharge systemMajor components of the ignition system are the flywheel, stator, trigger, capacitor discharge modules (CDM's) and spark plugsEach capacitor discharge module functions as combination switchbox and secondary ignition coil
CAPACITOR CHARGING #1 CDM
The STATOR assembly is mounted to the block below the flywheel and has CAPACITOR CHARGING COILS wound in seriesThe FLYWHEEL is fitted with permanent magnets inside the outer rimThe flywheel rotates the permanent magnets past the capacitor charging coilscausing the coils to produce AC voltage (260320 volts)The AC voltage is then conducted to the CAPACITOR DISCHARGE MODULES (CDM), where it is rectified (DC) and stored in capacitorThe stator voltage return path is through the ground wire of the other CDM and back through that CDM's charging coil wire to the capacitor charging coilsb c_