constant alarm

[reelknot]

I have a 2002 mercury saltwater series carb outboard. it is maintained very well.I took the boat out a few days ago in some rough seas(4-5 ft) on the way out the alarm went off(constant). I stopped the motor and turned the key half way on and the beep was gone.I pulled the crowl and checked oil tank as well as remote tank-all were full and tight.The motor was peeing fine with no problems.I started the motor again and maybe 5 min it did it again.I then fished in that area. When the seas were flat i ran 10-12 miles full throttle with no alarms going off. i continued to run the boat for 6-7 hours with no alarm sounding-motor ran and sounded great-why would it do this in rough seas?

 

[sschefer]

Re: constant alarm

I have a 2002 mercury saltwater series carb outboard. it is maintained very well.I took the boat out a few days ago in some rough seas(4-5 ft) on the way out the alarm went off(constant). I stopped the motor and turned the key half way on and the beep was gone.I pulled the crowl and checked oil tank as well as remote tank-all were full and tight.The motor was peeing fine with no problems.I started the motor again and maybe 5 min it did it again.I then fished in that area. When the seas were flat i ran 10-12 miles full throttle with no alarms going off. i continued to run the boat for 6-7 hours with no alarm sounding-motor ran and sounded great-why would it do this in rough seas?

A steady alarm is an overheat. The water pump was sucking air as the boat was pitching. Consider getting an offshore bracket or a Hydraulic jack plate installed on your boat. Lowering the engine in these condidtions may help.

 

[joed]

Re: constant alarm

Could be impellar. I had one the worked fine at high speed and peed at low or idle speed. However the blades were stiff and it was not pumping enough water to keep cool even though it was peeing at low speed. After 5-10 minutes of low speed the alarm would go off.

 

[reelknot]

Re: constant alarm

The impeller and water pump are new-every 3 years.I think that maybe i had the motor trimmed up to high...will be out this week again and will try to keep the trim down a bit. Thanks for all the replies.