2000 40HP EFI Problem

[sellboy74]

I have a that I bought a boat with a Merc 2000 40hp EFI four stroke. I am having a problem when I am idling there is a warning buzzer that that is sounding. It just started a few trips ago. It only does it when I am at the end of the trip for example when I am sitting in the watter idling waiting to load up at the boat ramp. I have good fuel, engine oil is proper level and fresh, it does not seem to be overheating with good stream coming out of the motor. is there any suggestions on the problem, trolling season is fast approaching.

[boats.net]

Could still be overheating. May have a stuck or corroded thermostat or clogged water passage. I would recommend purchasing a service manual, with that you can then specifically diagnose what the buzzer is going off about.