Heat caused problem on 1975, 25hp Evinrude

[muleskinner49]

Actually, owner caused problem by failing to check to see if motor was peeing.. but ... after going 300 yards, engine started sputtering, smoking, quit. Smoke was coming heavily from rear of engine, almost on fire around wiring. Once engine cooled, tried to restart to no avail. I don't have service manual but thought I should check compression first (engine did not lock), then work outward, i.e., firing, fuel, etc. Any advice is appreciated!

 

[kbait]

Re: Heat caused problem on 1975, 25hp Evinrude

Check compression. If it's low, it could be the head gasket, and you can inspect cylinder walls while you're doing that. Definitely step 1.

 

[OutboardDave]

Re: Heat caused problem on 1975, 25hp Evinrude

I second the compression check. In my experience I've had several motors that I've worked on and some that I've owned that have been overheated. 300 yards isn't very far to travel before seeing smoke and the works as you describe. Just out of curiosity, at what speed was the motor running, idle, mid-throttle, or opened up? If it did get that hot you probably will be replacing a head gasket at the very least. Hope all works out and please keep us updated.

 

[Texasmark]

Re: Heat caused problem on 1975, 25hp Evinrude

Can you specify more exactly where it came from....pulse pack, water jacket cover paint, wiring harness?

Reason I ask is that I have had engines overheat (stuck shut thermostats) and have been able to let them cool for 30 minutes roughly and they would readily restart.....until the final time on one when it siezed up tight as a drum.

If your's won't restart, the smoke could have come from the power pack(s) firing the plugs overheating because the engine block/waterjacket overheated, and could have gotten hot enough to overheat the electronics and cause them to fail whereupon you would not be able to restart the engine till you replaced them.

Mark

 

[14ftgrumman]

Re: Heat caused problem on 1975, 25hp Evinrude

Check compression and look for melted, burnt wiring. If wiring looks ok, try checking spark, with a spark tester, not just grounding a spark plug. If you have gas, spark and compression, it has to run. Two out of three doesnt make it.

 

[1946Zephyr]

Re: Heat caused problem on 1975, 25hp Evinrude

If you remove the bypass covers and exhaust covers, you can get a good visual of your pistons, to see if there is any scoring. A lot of overheated engines will get a lot of score damage on the pistons.

 

[Home Cookin']

Re: Heat caused problem on 1975, 25hp Evinrude

that sounds like an electrical problem--smoking wires and such. Are you sure it's a water cooling failure?