OaklandF4i
Darwin's exception
I have no more suggestions for freeing the piston than already mentioned.
My gut instinct is you may very well find the lower end in as bad a shape as the top. Acquired a YZ250 single lower end such poor shape from being left outside, that the growing corrosion inside between the crank and case actually put some tiny cracks in the cases (much like a growing tree under concrete.) In addition, if the crank is really frozen AND corrosion has built up around it between the case, whacking the piston hard and freeing it may only damage the crank, rod, and or case too as the force is transmitted to them.
I don't have a ton of experience with really old and frozen stuff. Just my limited experience. Based on that, I think i'd likely proceed with collapsing the piston if none of the above suggestions work in relatively short order.
Confident it could be done is such a way as to not destroy the crank and or rod as well. Really no reason in my mind not to proceed that way.
Just my opinion.
My gut instinct is you may very well find the lower end in as bad a shape as the top. Acquired a YZ250 single lower end such poor shape from being left outside, that the growing corrosion inside between the crank and case actually put some tiny cracks in the cases (much like a growing tree under concrete.) In addition, if the crank is really frozen AND corrosion has built up around it between the case, whacking the piston hard and freeing it may only damage the crank, rod, and or case too as the force is transmitted to them.
I don't have a ton of experience with really old and frozen stuff. Just my limited experience. Based on that, I think i'd likely proceed with collapsing the piston if none of the above suggestions work in relatively short order.
Confident it could be done is such a way as to not destroy the crank and or rod as well. Really no reason in my mind not to proceed that way.
Just my opinion.