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I have a leaking cylinder base seal which needs to be replaced. So, with everything on the engine removed to facilitate the withdrawal of the cylinder, as yet I haven't been able to budge it. I can wriggle it very sightly, there is movement! But it refuses to come down.

I haven't and won't attempt to use anything to prise it out. It has been suggested that I pressurise the cylinder, with air (with both the valves closed) and hopefully force a downward movement of the cylinder.

Has anyone employed this method? Or does anyone have any other suggestions?
You need a box of shed matches.

Apply from a distance, preferably with kerosene to assist the removal of the cylinder and then fill in the insurance form...... Missing, one Gypsy Major equipped aeroplane :mrgreen:
Rob L liked this
I'd try as johnm suggests first. You could try warming the cylinder externally using an electric heat gun to get it to expand a bit.

If you do use compressed air be careful how much pressure you apply, if it lets go with a lot of pressure behind it, it will go with a bit of a bang. There is quite a lot of surface area in the cylinder.

Would suggest some sort of restraint to prevent cylinder dropping off!

But, you really need to identify why it is binding first so you don't damage something.
Robin500 liked this
How many hours are on the cylinder ?

It could be that excessive wear at the bottom of the cylinder is causing the piston rings to jam the piston in the cylinder, be careful forcing anything as you will damage the cylinder wall.

Get a load of oil into the cylinder via the spark plug holes and wiggle gently until you feel the rings start to ride up the ridge in the cylinder wall.