Posted by Gordon Maney on Wednesday, February 13, 2002 at 2:01AM :
In Reply to: stuck flathead engine posted by jyotin on Monday, February 11, 2002 at 9:04AM :
Remove spark plugs, pour in generous amount of penetrating oil in each cylinder. Allow to stand for several days.
Raise one rear wheel with a jack and support with a jack stand. Put transmission in 4th gear.
Use the raised wheel and tire assembly, by rotating it back and forth, as a flywheel to apply your force. There is enough lash in your drive train to allow considerable movement. It works really great. It works even better on old tractor, given the mass of the wheel and tire assembly.
Back and forth, back and forth, and so on. It allows you to work it both ways, and is better than prying on things.
If that does not work after a while, remove the head and deglaze the cylinders above the pistons in each hole. Use, preferably a ball hone (aka dingleberry hone) and a lubricant.
Worst case, use sand paper. Soak it and try it again. it is usually the rust above the piston that is sticking it.