Piston Stuck inside the Cylinder

[Michael Muribi]

Piece by Piece dismemberment of my 94 YAM C75TLRS have (thanks to some good input from you) reached the very last step - the EXTRACTION of the Top PISTON from the inside the Cylinder - the very cause of the problem that made the dismemberment necessary. Methods tried -so far-, Push, Pull, Rust removing chemicals, Lubricants, Hammering via a wood intermediary. This thing is not budgging. I also tried little heating of the Cylinder wall. But I am apprehensive about overheating the Aluminum Cylinder -I do not know when to stop. I am also apprehensive about the use of a Hyraulic Pressure -it may crack the Cylinder???

Any last advice before deciding to scrap the Piston with the EXPENSIVE Block.

TKS

[99yam40]

I take it all the other pistons are out and you are just working on the last one.
What caused to lock up, as the piston is already scrap metal and maybe the block is also if it is that welded in.

BFH and 2x4 or punches to get it moving or break the piston to pieces

[Michael Muribi]

Ran motor with "Fresh/Well" Water to flush Salt Water out after use. And stored it outside (in Florida) for 2-3 Months. Motor will not Turn/Rotate via Starter or Manual after that. Signs of Water damage is very evident -no Gasket Material Left anywhere inside. Willing to sacrifice the Piston. But, I would like to Recover the Block, if possible at all.

I am not an OB Mechanic. I'm was a Computer Guy and a Weekend mechanic at best. Retired now. But, Rebuilding this motor is somekind personal challange/acheivement for me. Buying a new Block is a sort of defeating this purpose and economically not feasible now.

Not familiar with the term "BFH" Is this some kind of a Hammer?

MM

[99yam40]

Yes, big F Hammer

What did the crank and bearings look like?

[Tucker]

Oh boy, thought everyone knew what a BFH was, learned that as a kid working on bikes. It escapes me how that motor seized after fresh water flush and layup. Thinking disconnecting the connecting rod from the crank, rotate the crank out of the way and whack that piston with a BFH.