1988-1995 Mercury Force 5HP Outboards Service Manual, 90-823263 793, Page 117Get this manual
ZBIM IGNITION SYSTEM 1Theory of Operation This system operates the same way as the older breaker point magneto systems except there are no breaker points or condensersThe triggering mechanism is encapsulated in the coil assembly to form compact, self contained ignition systemThe primary windings of the ignition coil are charged by the flywheel magnets the same way as the coil is charged in breaker point systemThe flywheel magnets also activate smaller trigger coil, which is encapsulated within the body of the coil assemblyThis trigger coil, in turn, activates an electronic switch (SeR), which opens like set of breaker points and allows the magnetic field in the primary windings to collapse, generating high voltage in the secondaryThe high voltage in the secondary of the coil is released through the spark plug lead and jumps the gap in the spark plugNOTE: There were two different 81M ignition systems used on the H.PengineSystem has flywheel with the magnets glued on it and the coils have blue and brown primary lead wiresSystem II has the magnets machined recessed into the flywheelThe coils have gray and black primary lead wiresSee wiring diagrams