Old engines...Great; Friends...not so much!

weasel897

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Joined
Feb 7, 2012
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12
I have a 78 Evinrude 15hp outboard that I let some friends borrow to duck hunt. We've all hunted and have been around boats/outboards since kids so I didn't think anything of it.

Long story short, they ran it for a while after the impeller broke up and quit peeing water. The guy driving says that it started to smoke so he shut it off. I'm not sure if it was real smoke or just steam.

I guess my question is: What kind of damage am I looking at? Where should I start?

P.S....I haven't gotten the outboard from them yet, but will have it soon. (I'm in another state)

Weasel
 

kbait

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Nov 13, 2007
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2,452
Re: Old engines...Great; Friends...not so much!

Hopefully it didn't seize up. If it still spins over w/compression, you may be fine. You may want to get compression #'s. If one or both is low, you could have a bad head gasket (common w/overheat event). If you have no spark, you may have a fried CD box (again, common w/overheat). Check all wires for melted sheathing.. isolate and tape up, or replace if really bad.

When you replace impeller, check housing and plate for wear. Also, check out the lower water-tube grommet. If the old impeller disintigrated, find ALL the broken veins to be sure nothing's lodged in a cooling passage.

Good luck!
 

weasel897

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Joined
Feb 7, 2012
Messages
12
Re: Old engines...Great; Friends...not so much!

Hopefully it didn't do too much damage as he said he shut it off and it didn't die on him. He didn't think that it was seized up. Then again, I won't know until I get it from them.

They did buy a replacement impeller, but haven't put it in yet. I'm going to get it from them before they do any work to it. I'd rather do it myself and know that it's done right.

Thanks,
Weasel
 

1946Zephyr

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Joined
Oct 21, 2008
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5,556
Re: Old engines...Great; Friends...not so much!

Yikes. An overheat is not a good situation. Low compression can also mean badly scored pistons, which is another end result, from an overheat. If it started smoking, then that's bad news.
 

Home Cookin'

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May 26, 2009
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9,715
Re: Old engines...Great; Friends...not so much!

you really won't know if it's damaged until you run it on a boat, high speed, for 15 minutes or so. sometimes the warpage shows up when the block heats up.

Your friend should offer to get it checked over professionally and either fix or replace (with a used motor) IF they kept running it after they knew the impeller broke. On the other hand, if you would have kept running it, too, then it's one of those things. in other words, was it really the operator's fault, or one of those things that happens to old motors?

And before people get all judgmental, as a duck hunter (marsh boater) myself I know that frequently the tell tale gets clogged and stops running while the motor is fine, so it's not unusual (granted, not the bes thing) to run that way, or not to notice.
 

1946Zephyr

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Oct 21, 2008
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5,556
Re: Old engines...Great; Friends...not so much!

If the compression numbers look sketchy, then you can pull the bypass covers and exhaust cover and get a good visual of the pistons. 99% of the time, you can see the damge, through the ports. Discoloring of the paint on the head, is a good indicator of severe overheating too.
 
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