Another OMC story

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mercaholic
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Another OMC story

Post by mercaholic »

So a guy comes over with an early '60s Gale 5hp fishing motor that over-heats.

I've always refrained work on the OMC's but this story didn't sound right as the guy says it pumps strong but over heats. Sure enough we dropped it into my test barrel and fired it up. There was a visible torrent of water exiting the outet midway up on the leg. The water was quite hot to touch and eventually there was considerable steam forming. The motor slowed down so we shut it off. We removed the lower unit and noted that the impeller looked in good shape but changed it out anyway. Ran it afterwards with the same results.

Any idea why such a strong flow of water was exiting the motor yet things were getting very warm.
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Ray111
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Location: Prattville Alabama

Re: Another OMC story

Post by Ray111 »

I have an 1966 18 evinrude that had a similar issue.. there was dirt dobers built a nest in the water lines on the head.. I had to get a wire and clean out the nest. after cleaning no change in flow but the water was cooler and it did not overheat!
Ray Pieper
Prattville Alabama
Mark 20, Mark 15,Mark7 KE7, KG4, KE4, KF5 and Merc 150
mercaholic
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Re: Another OMC story

Post by mercaholic »

Ray111 wrote: Mon Aug 01, 2022 6:14 pm I have an 1966 18 evinrude that had a similar issue.. there was dirt dobers built a nest in the water lines on the head.. I had to get a wire and clean out the nest. after cleaning no change in flow but the water was cooler and it did not overheat!
Thanks Ray.

The motor did sit in a barn for a number of years so things could have made their way inside.

I may take a garden hose to the water tube and see if things flush out.
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Tom Brockmeyer
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Re: Another OMC story

Post by Tom Brockmeyer »

John, try to find an exhaust port cover gasket(s) and remove the cover. Those engines have a complicated water routing around the exhaust and may have a bad gasket allowing exhaust to blow the water out of the jackets before it has a chance to cool the block...
Lake Lanier, 30miles North of Atlanta, GA
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mercaholic
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Re: Another OMC story

Post by mercaholic »

Tom Brockmeyer wrote: Tue Aug 02, 2022 1:21 pm John, try to find an exhaust port cover gasket(s) and remove the cover. Those engines have a complicated water routing around the exhaust and may have a bad gasket allowing exhaust to blow the water out of the jackets before it has a chance to cool the block...
Good suggestion... :arrow:
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