Question; my boat just turned 20 hours and the audible alarm went off. Like the mechanic I am; checked all the fluids, found nothing out of the ordinary, un-plugged the alarm and went on with my boating. Later I plugged the alarm back in and it didn't alarm (beep) any longer. Any ideas?
What was going on at the time. The Merc motors pretty much protect themselves when you hear that alarm. The alarm tells you that there is something wrong but at the same time it protects itself as much as possible. Were you at full throttle? You may have been overrevving the engine. The Mag only goes to 4800 rpm. After that it will give you the alarm but it won't hurt itself.