Mercury Mariner Service Manual 6, 8, 9.9 210CC Sailpower, Page 14Get this manual
Ignition System DESCRIPTION The ignition system is an alternator driven capacitor discharge systemMajor components of the ignition system are the flywheelstator, trigger coilswitch box, ignition coils, and spark plugsThe flywheel has permanent magnets mounted in both the outer rim and the center hubThe stator assembly is mounted below the flywheel and has low speed (LS) and high speed (HS) capacitor charging coilAs the flywheel rotates, the magnets mounted in the flywheel outer rim pass the LS and HS capacitor charging coils, creating voltageCoil output voltage is indicated in the waveform diagram, shown belowThe voltage created charges the capacitor, which is located in the switch boxAs the flywheel continues to rotate the magnets in the center hub pass the trigger coil, creating AC voltageThe voltage tu rns on one of the two electron ic switches (SCR) in the switchboxA positve voltage pulse turns on the (SCR) switch associated with cylinder No.1; negative voltage pulse turn on the SCR switch associated with cylinder NO.2The SCR switch discharges the stored capacitor voltage into the primary side of the respective igntion coilThe ignition coil multiplies this voltage to value high enough to jump the spark plug gapThe preceding sequence occurs once per engine revolution for each cylinderSpark timing is changed (advancedretarded) by rotating the trigger coilwhich changes the trigger coil position in relation to the magnets in the cneter hub of the flywheelThe stop switch (or ignition switch) shorts the output of the stator to ground to stop the engine