175 Evinrude Overheating

1972 Robalo 19' CC w/ 1983 Evinrude 175

2 weeks ago I took a trip to Hilton Head and after a long day of 3'-4' swells and 20 mph winds I was cruising back through a long stretch of no wake zone and I believe my motor overheated. I smelled something like burnt hair and looked back and saw more than the usual amount of smoke. I immeadiately turned the motor off and trolled back to the boat ramp on the minn kota (which took about an hour). I figured the motor should be cooled off by then so I started her up and everything seemed ok.

The next day I cruised through the bay for a little while at around 25mph no problem. After about an hour the motor choked out and was difficult to start again. Once I got it going she would only run 10mph at full throttle all the way back to the ramp.

Once I got home I hooked the motor up to the hose and started it up. It sounds like its running pretty crappy so I do a compression check.

Heres what I got:
1) 55 1) 87
2) 92 2) 95
3) 95 3) 90

Any ideas as to what could have caused it to overheat?

Im not really sure where to go from here, but im afraid I may be looking at a rebuild / repower situation.

Re: 175 Evinrude Overheating

Could just be a headgasket situation. or a stuck ring,,prolly not.
I'd pop the head and look see.

Causes of overheat?
what is the service history?
Waterpump old?
Could also be water deflectors in the head, bad t/statm , clogged carb.

Re: 175 Evinrude Overheating

Im not sure what caused the motor to overheat, i was just chuggin along in a no wake zone when it happened. I had a new water pump and seal kit put in June '08.

Re: 175 Evinrude Overheating

Would be interesting to see what the inside of the thermostat housing looks like on the low compression head. I'd also pull the intake side cover on #1 and see what the piston and rings look like from the side. Did you have any water coming out of the telltale during all this?

Re: 175 Evinrude Overheating

As far as i know it was peeing. The thermostats have been removed so i dont know if that had anything to do with the overheating.

Re: 175 Evinrude Overheating

Heres the plug from the bad (55psi) cyliner





This is the outside of the plug from the #1 cylinder on the opposite side