Stuck piston

[ubxf]

I was able to open up the engine but i still can't move the shaft it looks like the pistons are stuck. What is the best way to extract them without breaking them?
Are they still usable?

[Al Schober]

The rings will corrode and stick themselves to the cylinder walls. Penetrating oil & time are your friends in this case. Are you in a hurry? I freed up a 'throwaway' lawnmower, but it took a month!
While waiting, you can remove the crankshaft. That way it won't be keeping the pistons from moving.
Once the crank is out, you can go with the 'big guns' - a piece of 2x4 and a hammer. Look at the piston from the bottom and you'll see where it's strong and weak. You don't want to crack the top of the piston or break off one of the lands between the piston rings. If you do, problem is over - you need a new piston. No biggie - they're available.

[lat 64]

I understand you may have a shop do machine work on this, Consider the whole shortblock done by them. Or at least let them do the teardown. They can assess whether the piston is salvageable or not. They may have more experience on just how much judicious effort to remove those pistons without ruining them. Of course, they might be junk at this point and a non-starter.

If you bring the shop a basket of parts, remember to document or label EVERYTHING as it was insitu.

Not all machine shops are good. My engine was brought to a "marine" shop by the PO and they put the pistons in backwards, pistons in reverse-order, standard-size main bearings on a reground(undersize)crankshaft, and forgot to install main nut on reduction gear,

[ubxf]

Ok thank you guys, i'll stop for now and bring my project to a specialist for evaluation