Low Oil Pressure?

[lunasea9]

I just got back from the coast where I had a low oil pressure light and alarm go off on one of my outboards (1999 Yam. F100's). It would only come on after running for 10 minutes or so at crusing speed and then throttle back to idle. As soon as the RPM's dropped it would light up and beep. If I put the motor in netural it would stop only to start up again if I put it back into gear. But if I let it idle for a few minutes (alarm off), I can put it in gear again without the alarm. They have approx.580 hrs and are well maintained. Is it a sending unit or idle rpm thing or what? Please help........Thanks in advance

 

[BRIAN03]

Re: Low Oil Pressure?

I know it sound crazy but that engine doesnt have oil pressure problems. I would bet its two reasons. One the hours on the oil . Two the type of oil being used. Yamaha specs a special oil for there four strokes. I would change the oil and make sure who is doing it is using good oil and to spec. I would change the oil every 50 hours. good luck