1982 Johnson 115 - One cylinder with no compression

MHHPartner

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While boating last weekend engine lost power at some point. Still sounded OK but would not pull tubers. No foreign noises or excess smoke. Ran compression check when I got home and had 3 cylinders at ~120 psi and one at 0 (didn't move gauge). Put some oil in cylinder and cranked again. Showed 30 psi. Pulled head. Head, piston crown, and cylinder all look perfect - no nicks, scoring, etc. Piston does not appear to have any more side play than the one right below it.

Has anyone ever seen a ring break and cause no visible damage? Or is there anything else that could cause this situation?

Thanks for any help or guidance.
 

silverfox441

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Apr 3, 2011
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Re: 1982 Johnson 115 - One cylinder with no compression

Stuck/broken ring sounds about right. A cracked cylinder wall might not be visible but i don't know if that's possible on them engines.
 

boobie

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Re: 1982 Johnson 115 - One cylinder with no compression

What's the head gasket look like ??
 

MHHPartner

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Re: 1982 Johnson 115 - One cylinder with no compression

What's the head gasket look like ??

Head gasket looked perfect. No signs of leakage.

I'm going to measure the bore today since I don't know all the history of this engine and see what my options are.
 

boobie

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Re: 1982 Johnson 115 - One cylinder with no compression

Dumb question, did you try another compression gauge ?? If it's a cheapo they can take a dump.
 

MHHPartner

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Re: 1982 Johnson 115 - One cylinder with no compression

Sorry, folks. Found the cylinder damage tonight. Broken ring over a port. Somehow missed it in the shadows during my first inspection.

Thanks for your replies. My apologies for wasting your time.
 
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