2001 Mercury Mariner 50-60HP Factory Service Manual, Page 80Get this manual
IGNITION
Flywheel Assembly
The flywheel assembly contains six permanently charged magnet segments which are bonded and retained to the inner wall of the flywheelEach magnet contains north and south pole providing 12 pole system
Ignition Coils
The primary (+) side of the ignition coil receives voltage discharged from capacitor in the ignition (CDI) circuit located inside the ECMThe voltage is multiplied by the coil until it can jump the spark plug gapEach ignition coil will produce high voltage spark at each crankshaft revolution, producing spark at each cylinder at the proper time (pre-determined by the ECM)Ignition coil maximum output is approximately 40,000 volts