1985 Evinrude 140 trouble melted thermostats

[lekslk]

HI There,

I bought a Evinrude 1985 140 VRO, & have been checking it out for use in the spring. I pulled the thermostat covers off & the whole water cavity is full of what looks to be melted plastic & the thermostats were stuck in the mess both out of there seats. The previous owner said he put a new water pump in it & gave me the old one, & he said it pumped water fine. I only looked cause the coil wires had melted insulation on them where they touched the block. What should I do, I don't know if I can get all the stuff out of the waterports in the head. Any suggestions would be greatly appreciated. Could it be calcium deposits there's no plastic anywhere around that area.
Thanks,
Lance

 

[emdsapmgr]

Re: 1985 Evinrude 140 trouble melted thermostats

Sounds like the engine was seriously overheated. Before you put any $ into the engine, you should do a compression check to be sure the powerhead is still good. If compression is ok, you will probably want to replace both thermostats and the nylon (plastic) pressure relief valves and the grommets in the thermostat housing. Make sure you check the pinhole(s) in the valve body-they need to be open. The water flows thru the block, then dumps into the thermostat housing before going back into the lower unit. You can have great powerhead water pressure, but if it can't get through the thermostat housing, you will get an overheat.

 

[lekslk]

Re: 1985 Evinrude 140 trouble melted thermostats

Thanks for the reply, After seeing the melted stuff I was going to pull the heads to see what the cylinders looked like & try to get all the melted plastic out if I can, but I suppose I should check the compressoion before I pull the heads. Do you happen to know what the compression should be? Could the motor still be ok?
Thanks,
Lance