Trouble replacing cylinder head on 2 cycle 5hp Seaking

Joined
Apr 11, 2011
Messages
6
After a successful season on the lake, I had to pull my 1951 Seaking 5hp back into the shop. I replaced the top piston and put new rings on it to resolve a complete loss of compression on the top cylinder. The problem I need help with is that I'm not able to get the pistons back into the head. I cleaned out both cylinders and oiled the pistons and have been trying squeeze one ring at a time and drop the pistons back into the head- no luck. After scratching my head a couple of weekends on this, a hammer's starting to look tempting, but I'm sure there's a smarter way to do this. Also, my local parts store doesn't have an equivalent gasket for Johnson or Evenrude. Is there anywhere else I might look to find one?

Thanks,

Frustrated,landlocked and drydocked
 

nwcove

Admiral
Joined
May 16, 2011
Messages
6,293
Re: Trouble replacing cylinder head on 2 cycle 5hp Seaking

not quite sure what the exact problem is? pistons to tight? rings to tight? rings just wont behave themselves long enough to go in? ive used a hose clamp to compress rings while sliding them into the cyls. just tignten it enough to compress the rings but loose enough to slide off as the piston goes in.
 

xjdriver

Petty Officer 1st Class
Joined
Sep 10, 2012
Messages
341
Re: Trouble replacing cylinder head on 2 cycle 5hp Seaking

Or get a piston ring compressor for small engines, dont use the hammer.
 

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
Re: Trouble replacing cylinder head on 2 cycle 5hp Seaking

Remove rings from piston, then insert each ring into the cylinder, carefully checking for "ring gap"....should be a few thousands of an inch.....if not then grind sufficient off of ring to allow for gap....otherwise you will break rings trying to install. Are you certain also that you have rings with gaps at their respective groove locator pins?....again, if not, rings will break upon assembly....
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: Trouble replacing cylinder head on 2 cycle 5hp Seaking

Well landlocked, here is the true scoop. You will have a helluva time getting those pistons in there without the special tool ring compressors. Ordinary ones won't work because the must be removed AFTER the pistons are in the holes.
 

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xjdriver

Petty Officer 1st Class
Joined
Sep 10, 2012
Messages
341
Re: Trouble replacing cylinder head on 2 cycle 5hp Seaking

Well landlocked, here is the true scoop. You will have a helluva time getting those pistons in there without the special tool ring compressors. Ordinary ones won't work because the must be removed AFTER the pistons are in the holes.

Hmm i see, what if you removed the pistons from the con rods and used the std compressor, put them in the cylinders, then slid them out just enough to install the wrist pin and clip? That is assuming they are floating pistons. Its what i did on my vw, lol. But it looks pretty tricky on that motor.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: Trouble replacing cylinder head on 2 cycle 5hp Seaking

The wrist pin is a slip fit on one side of the piston, and a press fit on the other side. Best bet without the tools is to improvise with a hose clamp and beer can. The hose clamp can be opened and removed once the pistons are in the bore.
 
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