1985 Mercury Outboard V-300 V-3.4L Shop Service Manual, Page 24Get this manual
PARTIGNITION SYSTEM Description Th V6 outboard ignition system is alterna to r-dri ven with distribu lor-less capacitor dischargeMajor co mponen ts of Ihe igni tion system are th fl yw heel, stator asse mbl ytri gger assembly5wilchboxes, ignit ion coils and spark plugs
Th sla tor assembly is mo unted stationar below th flywheel and has capacitor hargi ng coilsThe fl ywheel is fill ed with permanent magnets inside the oute rimAs th fl yw heel ro tat es th permane nt magnet pass th capacit charging coilsT his cau ses th capacitor charging coils 10 produ ce AC voltageTh AC voltage then is conducted to the where it is rectified and stored in capacitorThe trigger assembly (also mounted und er th fl ywh eel) has coilsT he flywh eel likewise has seco nd se of permanent magnets (located around the center hub)As the yw heel rotates the second set of magnets pass Ihe trigger co ilsTh is causes the trigger coils, illluTnto produ cea AC voltage that is conducted to an electronic swit ch (SCR) in the switchboxThe swit ch discharges the capacit or vol tage into th ign iti on coil at the correct lime and in firing order sequenceCapacitor vo ltage is conducted to the primary side of the ignitio coilTh ignition coil mult iplies this voltage to value high enough to jump th gap at the spark plugThe preceding sequence occurs onceperengi ne-revol ut ion for each cylinder Spark timing is changed (ad vancedlreta rded) by rOlat ing the trigger assembl which changes each tri gger coil positio in relat ion to th permanent magnets locat ed arou nd th fl yw heel cent er hubWI