Expert: tyler boehner - 3/7/2008

Question
When I start my boat the alarm wont shut off.Everything runs great but the cherping noise drives me crazy!Allthough, when the boat is in gear and at high rpm's it will shut off.But it will come right back on when I back off the throttle, Can you help me????      Thanks Seth

Answer
A motor model and year would help greatly but there are a few things that set off an alarm on all motors.  Being a Maria, I can only assume that it is an I/O mercruiser engine.  If the alarm goes silent at full throttle, I also have to assume that the low oil pressure sensor is what is triggering the alarm.  When the engine is at a low rpm, the engine will have a weak oil pressure if the oil pump is weak, the oil filter is plugged, or a number of other reasons.  Low oil pressure will come up when the engine rpm goes up.  It is probably a warning horn that is going off.  If you find a dealer, assuming that you have a mercury engine, that is a mercury dealer, they should have a CDS or DDT.  CDS and DDT systems are computers that can plug into your engines computer and tell the dealer why the alarm is going off.