overheating 63 evinrude 40 hp

[Patrick in wa]

my outboard seems to be overheating. When I start the outboard water will come out of the telltale after about a minute of warm up, but it is very hot. To hot to keep my hand under the water for more than a second. The paint around the cyclinders is peeling. bad. :facepalm:

I took the tstat out and put it in some water on the stove. opened up right at 145 degrees.

I'm not sure what to do next. I know the impeller is working because its peeing water. I know the tstat is working correctly. I know that the water is circulating around the power head because the water is coming out hot. I'm gonna go down to the dealer and get a head gasket so I can check water passage ways and I read somewhere that a bad head gasket might cause it to overheat (don't know if thats true but I'm only getting about 90 psi in both cyclinders so I figure a new head gasket cant hurt).

The only other thing left to do is drop the lower unit and check the impeller but it seems to be pumping water ok and the previous owner (said he) replaced it right before I bought it.

Does anybody have any other suggestions?

Anything else I should do while I have the cyclinder head off? I can't find any info on changing the head gasket. I'm hoping its as straight forward as it seems(famous last words).

Thanks everybody for your help.
Patrick
(can post pics if helpful)

 

[RogersJetboat454]

Re: overheating 63 evinrude 40 hp

I know the impeller is working because its peeing water.

The only other thing left to do is drop the lower unit and check the impeller but it seems to be pumping water ok and the previous owner (said he) replaced it right before I bought it.

Does anybody have any other suggestions?

You know what they say about assumptions, right?
Don't assume. Start with the basics, and pull the lower to inspect the impeller. The tell-tale is not the tell-all. We know that the impeller is moving water, but is it enough water? Or perhaps the water pump housing is gouged to death, and is in dire need of replacement. Won't know until you look.

 

[Patrick in wa]

Re: overheating 63 evinrude 40 hp

Did anybody else have problems with iboats these last two days?

I removed tstat and the motor ran just fine. peeing a lot more water without tstat than with tstat. water and head were warm but not to hot to touch. I thought that meant tstat was bad but after I installed new tstat water flow and head temps are the same as before.

Roger, thanks for your reply. Your right I should check impeller. Just seems odd that I had so much water flow without tstat in. Is that normal?

 

[boobie]

Re: overheating 63 evinrude 40 hp

If it was my mtr I'd check the impeller as you may not be getting enough volume or pressure.