Re: What is a trigger? (not the one from Winnie the Pooh!
More properly called a sensor assembly or a timer base assembly on a OMC motor, it is located under the flywheel. There are two different units (stator is the other one) that are located underneath the flywheel. The flywheel has two different sets of magnets cast into it. Just so you know, as a magnet's north pole and it's south pole "pass" by a wire winding surrounded by a iron "core", voltage is generated. The magnets on the outer perimeter of the flywheel, charge the stator windings and "charge" the power pak. The pack stores this voltage (approx 200 volts A.C.)and waits for a signal to release it to the ignition coils. The inner hub of the flywheel has additional magnets and these rotate next to some very small windings (or sensor coils). The voltage generated (approx 3 to 5 volts)by these small coils (sensors) tell the pack to release the stored voltage and send it to the ignition coils. An ignition coil will take the 200 volts and develop upwards of 20 to 40000 volts, hense, nice hot spark for the spark plugs. The flywheel and crankshaft are "keyed" together and that is what locates the ignition in relation to the mechanicals. IE: timing. If a flywheel key ever gets "sheared off", the timing is all out of sync in relation to the basic timing or Top Dead Center. Since the timer base rotates under the flywheel depending on throttle position, this gives you initial timing and advance timing. On Mercury motors, the sensors are called triggers but do the same thing. hOPE THIS HELPS.
