Mercury 40hp 4 stroke cuts out

[Alun]

The engine starts easy and there is water constantly running through it. I've checked the oil and thats ok. After running for about 10 minutes the horn emits a continuous sound and the engine cuts out. I believe this is an overheating warning. Can you help I am not mechanicaly minded. After cutting out I can restart engine easily enough but then it cuts out again.

 

[HSEMJ]

Re: Mercury 40hp 4 stroke cuts out

Just a quick question, how long do you run the engine after the horn starts sounding? A solid continuous tone indicates a over heat condition, the engine should also drop to 2000 rpm but not cut out. The over heat condition should be look into ASAP before engine damage is done. The cause of the over heat could be a worn water pump impeller, bad thermostat or a restriction in the water system.

hope this helps

 

[ronnieboy]

Re: Mercury 40hp 4 stroke cuts out

like hsemj said, change water pump,( no poppet )and thermostat, flush to remove blockage. should be good asnu. good luck ron