overheating 50 hp Evinrude 1988

[Gene Baker]

Engine has new water pump and I just replaced the thermostat, temperature senser and pressure relief valve. When starting in a barrel the tell tail has excellant flow and initially water flows out the slots in the rear of the exhaust housing. This water is warm and the top of the cylinder head is hot but not too hot. After about 10 minutes the flow out the slots get less and less and then stops and the overheat horn sounds. Any Ideas?

 

[5150abf]

Re: overheating 50 hp Evinrude 1988

jUst a geuss but could you have out the tstat in backwards, almost sounds like ti is woring backwards of what it should.

I have the same engine(81) and have done all that but don't remember if the tstat can be put in backwards, that is all I can think of, if it pumps water the pump is good and the head is clear, it just sounds like it is closing and shutting off the water.

 

[tashasdaddy]

Re: overheating 50 hp Evinrude 1988

water in barrel will get hot, from exhaust, running that long. put some muffs on it.

 

[Gene Baker]

Re: overheating 50 hp Evinrude 1988

Thanks I will check the tstat, But as I remember it would not go but one way. I was thinking that the muffs would pressurize the system and not give me a true reading on what pump was doing. No problem trying the muffs though. Some one had suggested a restriction before the engine that shows up as it heats up. Any thoughts on this?-----Gene

 

[Gene Baker]

Re: overheating 50 hp Evinrude 1988

I pulled the water jacket off again, the one around the engine head. The thermostat was in correctly. Found small particles in behind the thermstat Probably not enough to restrict water flow. Any other thoughts.------Gene