uses pretty much the same circuit on all of their current
engines, so what applies to one will probably apply to all.
I encountered extremely similar symptoms on our 55B4. Engine would shut off at unpredictable times. Always would re-start after re-setting the circuit breaker. I eventually changed just about everything in the circuit other than instruments. After the problem persisted even with both wiring
harnesses replaced, I observed what the problem was: upon starting the engine and letting it run at idle at the dock
, I saw a faint spark (arc) between the exhaust
manifold and the main wiring
harness. Sure enough, there was a worn spot in one of the wires in the harness where it sparked, thus shorting out the system causing the 20 amp breaker to trip. I insulated the wire with tape, enclosed the harness with wire loom (from any auto parts
store) suspended the harness, and haven’t had that problem in the four years since. It was maddening to find, and eluded me for three or four years, including interrupting one two week cruise
and canceling another. I checked the harness I removed and found a similar worn area.
That which doesn’t kill you will make you stronger and smarter.