What's the best way to un-seize a piston?

[Mursal]

We need a picture, I only have a limited imagination ............
Can you get anything between cylinder and block?

 

[John 1594]

Right, same principle as the filter strap....

this is assuming of course, that the flywheel is keyed solid to the crank, and not on a taper only fit like some villiers

Get a good rachet strap, thread this round the flywheel in such a way that when its tight, trying to tighten it more will want to turn the engine in the desired direction

If you cant move it by pulling direct on the handle, a decent bit of wood about 4ft long, through the handle and onto the flywheel

just try it gently to make sure nothing is going to slip, before putting more force on it

 

[stugordon321]

I'll get a photo tomorrow as don't have any.
Thanks

 

[Mursal]

That freeze spray idea, is interesting ...........
@ladycrofter

 

[Dry Rot]

Heat the cylinder with boiling water, put freezer spray down the spark plug hole, and try to turn the nut on the crank shaft with an air wrench on a very low setting so you are applying a regular vibration rather than a consistent heavy force. A series of small taps is more like to free something up than a consistently strong force.

Heating the cylinder will make it expand, using the freezer spray with make the piston contract. Then shake the beggar loose!

 

[REStracTORATION]

That freeze spray idea, is interesting ...........
@ladycrofter

We use that stuff for fitting the new liners in perkins
Easy job

 

[ladycrofter]

That freeze spray idea, is interesting ...........
@ladycrofter

We use that stuff for fitting the new liners in perkins
Easy job

Forgot to mention - wear heavy gloves just in case! WOuldn't want to end up doing a Ranulph Fiennes!