1983 evinrude 150 overheating problem

[dmscarp]

Hi Guys...Having trouble with my engine overheating. I took it out the other night and it ran great. Next morning it started blowing steam out of the telltail and overheating. I changed out the water pump, because it was time anyway, and have the same problem. I also have been running the engine without the therms installed so I know its not them. Pulled the heads today and found a little junk but not much. It seems there is a blockage somewhere but not sure yet. The water pump seems to pump awesome, great pressure from the telltail and exhaust but it turns to steam after 5mins of running. Any directions would be appreciated......I have attached pics of the heads removed it that helps. I did notice there are 3 rubber "blocks" in the passages on the outer water passage way on both sides of the engine. Why would these be there...they seem to obstruct flow ???

 

[Daviet]

Re: 1983 evinrude 150 overheating problem

The rubber blocks you are seeing are deflectors, they make the water circulate in a certain direction and should be there.
What did the head gaskets look like, could one of them have been leaking combustion into the cooling system causing your problem?

 

[boobie]

Re: 1983 evinrude 150 overheating problem

You need new water deflectors.

 

[Haffiman]

Re: 1983 evinrude 150 overheating problem

You might have a water leak in the exhaust cover/ gasket.

 

[boobie]

Re: 1983 evinrude 150 overheating problem

He should start with the deflectors first and go from there.

 

[Haffiman]

Re: 1983 evinrude 150 overheating problem

Look at pistons exhaust side port and stb. Port side totally 'clean', stb more in the normal. Mighr be a water intrusion from exhaust stb side.

 

[dmscarp]

Re: 1983 evinrude 150 overheating problem

Ok, the head gasket does not look that great and could be leaking so I will replace them. I will try to replace the exhaust cover gasket also but the bolts dont look friendly. I will also replace the deflectors. Do I need to send the heads out? Is there any way to make sure the passages are clear while having the heads off? Thanks guys...great help !!!

 

[dmscarp]

Re: 1983 evinrude 150 overheating problem

Ok, here are the results. I replaced the deflectors and the head gaskets and the engine is running at 100deg on the hose on each head. I also increased the compression by 10lbs per cylinder to an average of 110 and one cylinder at 95 which is the starboard bottom piston. I did notice a little scoring in the cylinder wall which I guess is causing the lost compression. i am going to put the boat in the water for the test but I am already sure by the temp readings the problem is solved. I attached a pic of the old deflectors so you can see how bad they were. Thanks for all the help, you guys are the best.....