I am new to this motor 40ELPTEFI having just bought a whaler which it is on. The engine has been service regularly at a mercury dealership. When I am at idle for an extended time cruising in our bay I get an alarm. It is a single tone and will not go off until I shut the motor down and start it again. It always restarts and the alarm is gone. I first thought this must be an overheat alarm. I took out the thermostat ( year old ) it had a little bit of corrosion I soaked it in vinegar and cleaned it off and reinstalled it. the pee stream is strong and changes with rpm. I ordered the shop manual and saw that the single tone could be for five different faults. I checked the ect sensor and it seems to be within range according to the manual. The pee stream is warm but not hot I checked the thermostat operation while the thermostat was out fully open 145 degrees. I have not had much of a chance to run the motor wide open but when I have it has not presented any problem. The motor received a full impeller kit in May by the dealer. What else should I look for? The motor will always immediately restart without the alarm. I'm a sailor and these bigger outboards are new to me. Oil is clean (May) no milkiness. Any help would be much appreciated. Thanks , George
