Evinrude 85hp Overheating issues

[pandorasales]

I need some help. I have a 78' 85hp Evinrude that is overheating. I was still getting water from the Tell Tale, but the overheating horn was sounding. The water from the telltale was hot to the touch, so I figured it was a Thermostat issue. I replace the thermostats and now I still have the issue.

I used a infared thermometer and the left side was getting around 200 degrees and the right side was 160 degrees. I only ran the motor for a few minutes before the temp was this high, the horn went off, and I shut it down.

I then removed the hoses that feed the thermostat housing and verified water was coming through the cyclinders on both sides, but the motor still had the same temperature characteristic as listed above.

What is my next troubleshooting step? I changed the waterpump last year and the water seems to be strong out of the tell tale. I am not sure how much water should be coming out of the hose to the thermostat, but it is coming out with about 1/2" of pressure.

Should I be checking for blockage? Could it still be the waterpump/impeller? Not sure where to go next.

Thank you,
Ben

 

[crb478]

Re: Evinrude 85hp Overheating issues

If you are sure the thermastats are good then you can pull the heads and make sure that the water diverters are still in place and not blocked or swollen. While the heads are off its a good time to check the water passage covers. Be careful removing these as the bolts are easy to break. You will need new head and water passage gaskets. You can do this for just the side getting hot, but for piece of mind I would do both sides. The telltale lets you know that the pump is working not that the water is getting to the heads properly.

 

[pandorasales]

Re: Evinrude 85hp Overheating issues

Thanks for the quick response. So the water coming out of the bottom of the block before going into the thermostat housing (not the tell tale) would not show if there is a blockage in the head? Just want to be sure before removing the head.