How to remove a stuck piston

[steve.clarke]

Yes if you use white spirit and WD 40 it's a low heat and the idea is to heat the whole lot uniformly,mine was well siezed in you can see the rust ring that was holding it.

[Paul Gasson]

Steve, I will give it a go over the holiday but my barrel is far worse than yours. I have enlarged a part of the previous photo to show the condition of the bore above the piston, by feeling under the base of the barrel flange I would say it is similar below the piston as well. I will let you know how I get on with it. Thanks for the advise,

Paul

[nevhunter]

Geez guys I'm not too happy to be belting blocks of wood etc while the piston is still hooked up to the rest of the motor. You have to dismantle the engine anyhow. Free the conrod from the flywheels and press the piston upwards where the bore has been scraped clear of rust.. Make a piece of wood to fit around the conrod which can be tilted to one side, or "G" gramp two pieces one each side of it and press on to the wood . Nev

[a.middleton]

As a last resort you can use a large hole saw to remove the top of the piston then a reciprocating saw to cut through the gudgeon pin.
Make sure the hole saws pilot drill doesn't hit the end of the con rod, once the top is off you often find they release.
Good luck
Andy

[pappleton]

My first bike, a'54 Enfield Clipper had been living in some ones back yard for years and the piston was rusted solid to the bore. On the advice of my father and a motorcycling buddy. we removed the head and filled the bore with diesel. It took over 2 weeks before it eventually freed up. I had it rebored and a new piston for the princely sum of £5. I had only given a box of 5 Tom Thumb cigars for the bike!
If the piston will start to move by rocking it in top gear, it will eventually do a complete revolution. I guess that you are going to strip it completely? Then you can remove all the muck from the crankcases.

[paul.jameson]

Paul,

One little consolation is that your cylinder is the same as all 350s from about 1934 through to about 1952, including all W/NG models. So replacement cylinders are readily available. If you talk to Pete Kemp he may even be able to source a new one for you. Equally, the con-rod is common to all 350s so a replacement would be easy to acquire.