Johnson A-25 Cylinder

[willyboy]

I have a few different projects going at the moment and have a question on a seized Johnson A25 cylinder. The coolant plug is missing from the end of one cylinder and I plan to replace it with a 1924 copper wheat penny pressed into the plug recess. Does anyone know if I should use some form of adhesive to keep it in place other then pressing it in place? I was thinking of using Indianhead gasket sealer,yay or nay,any suggestions? I’d like to plug this up before I fill the cylinder with 50/50 mix of tranny/acetone to try and unstick her.

[PM T2]

The freeze plug in the end of the cylinder has nothing to do with the stuck piston or cylinder bore. If you put any type of fluid in the cylinder and it leaks into the water jacket, you have bigger problems than just a stuck piston.

I’d advise you to go ahead and try to get the piston unglued, and save the effort of installing the once cent freeze plug until such time as you know the cylinder is actually salvageable. Having that hole open also lets you see if the unseizing elixir is indeed leaking into the water jacket from the combustion chamber. Long and short of it is, if you have oil leaking out of the combustion chamber and into the water jacket, you have a split in the cylinder wall, and therefore, a cylinder that is likely beyond redemption.

Just my $0.02

Best, PM T2

He's livin' in his own private Idaho..... I hope to go out quietly in my sleep, like my grand-dad did..... and not screaming, like the passengers in his car...

[Tubs]

You might find this useful in getting your piston
free. This just happens to be a Model A Johnson.
This motor sat in a dirt floor metal shed for
decades. It was a battle getting it out. I suspect
once yours breaks free it will slide right out.

https://www.youtube.com/watch?v=QcAwNp0mzRs

A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.

[willyboy]

Thanks Tubs,i may give that a try if I have trouble. I’ve been lucky with 2 previous engines that had the same problem by filling them and letting them sit and then applying some heat to the cylinder with an old hair dryer gun. After a few cycles of that over a week or 2 I can usually get them unstuck with a little patience and a breaker bar on the flywheel nut.

[1946zephyr]

That is a very clever trick. Just hope and pray that one of those ears don’t snap off the jug : 😮

[bkrsdoz]

I performed a similar cylinder removal like Tubs on a ’35 Evinrude Sportsman.
Take your time, and easy does it.
It worked well for me.
Bob

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