Merlin2166
New member
I have a 60hp Mariner EFI 4 Stroke It starts and runs okay up to 4000 revs then the water over heat alarm goes of, I then put it in neutral for 3 secs and its okay again. It runs okay at lower revs with no problem. I water tell tail is good but it drops slightly after running at speed. It even ran for 20 miles with no problem at all. The engine has been well serviced and maintained, its used on the sea but has not been run into the beach or sand ect. The water pump and impellor are good, the engine water ports are all clear, the thermostat is working okay. The engine is always flushed out with muffs on a regular basis. what might the problem be ! Can any one advise please.