1987 110 Johnson 60 psi in all cylinders

whalerfreak22

Petty Officer 3rd Class
Joined
Jul 16, 2008
Messages
76
Hello all I just bought a 110 powerhead.I did a compression check when I got it and it has 60 psi in each cyl.I popped the heads off seeing that it had been rebuilt with .30 pistons.the bottom right piston has 3 small dings like a piece of foriegn metal got in there.they are near where the exhaust exits the block.I also shook all the pistons to see if there was any slop in the engine and 2 pistons were 'loose' ,like they'd knock if you started it.what do you guys think should I rebuild it again or decarb it?
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,930
Re: 1987 110 Johnson 60 psi in all cylinders

If your guage is correct, 60 psi is to low for engine to operate correctly. The small ding could be a piece of a reed ,wrist pin bearing or ring locating pin. I myself would not run it and would disassemble it and throughly inspect it..
 

Sixmark

Master Chief Petty Officer
Joined
Jul 11, 2010
Messages
890
Re: 1987 110 Johnson 60 psi in all cylinders

Ok you shook it and 2 pistons were loose, I think you already answered your own question here.

Would you run it with parts missing, because they will be missing eventually if you do.
 

whalerfreak22

Petty Officer 3rd Class
Joined
Jul 16, 2008
Messages
76
Re: 1987 110 Johnson 60 psi in all cylinders

Also forgot to mention that whoever rebuilt this powerhead I don't think they knew what they were doing.all of the cyl walls are scratched like someone took a piece of sandpaper and swiped it.looks more like when a cd gets scratched.and thanks for the imput so far I will split the case today.
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,930
Re: 1987 110 Johnson 60 psi in all cylinders

Sounds like Siezco pistons....not enough clearance.
 

whalerfreak22

Petty Officer 3rd Class
Joined
Jul 16, 2008
Messages
76
Re: 1987 110 Johnson 60 psi in all cylinders

So a decarb is useless on these 2 pistons?could it be possible the rings are stuck causing the pistons to shake?
 

Sixmark

Master Chief Petty Officer
Joined
Jul 11, 2010
Messages
890
Re: 1987 110 Johnson 60 psi in all cylinders

I think you are hoping for a best case scenario here when there really isn't one, you have 2 loose pistons and heavy scoring of the cylinders.

The best thing in this scenario is to rebuild it if you want to put the money into it.
 
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