How to free a seized HT piston?

[mbatl]

I'm working on a HT bike for someone who doesn't know much at all about the mechanics of these engines. He ran regular gas in the HT because he ran out of 2 cycle gas away from home and of course it seized.

I have the cylinder jug loose but the piston is stuck in it and wont budge.

Whats the best way to free the piston so I can continue disassembling the engine? I tried PB Blaster but so far no luck.

In this situation, the cylinder jug where the piston rings froze is trash correct?

 

[Lunardog]

I would say thats a fair assumption. If it got to the point the rings actually siezed to the cylinder walls the jug is shot. Piston may be salvagable and thats a big maybe . The rod and crank bearings will need inspecting too. Best I could suggest is soak it for a day or two hitting it with the PB blaster spray a couple times and then try to drive the piston out with a block of wood and a hammer. Unfortunately at this point its a **** shoot what can be saved. Good luck.

 

[mbatl]

Thanks for the response. After leaving with pb blaster awhile then torching it I was able to get it out with a huge iron stake.

Now I'm researching top end rebuild kits and researching what special tools and special techniques are required.

 

[Cavi Mike]

Just pound it out. Nothing there is salvageable. It's like $50 for a brand new slug and jug. To bore and re-coat that cylinder will cost way more money than any of it is worth and then you'll have to source an over-sized piston as well...good luck with that.