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The 2-Stroke Garage => Turning Wrenches => Topic started by: gwcrim on February 09, 2026, 09:44:12 PM

Title: Stuck Montesa cylinder
Post by: gwcrim on February 09, 2026, 09:44:12 PM
Hi all.  I'm back with yet another two stroke project.  This time it's a 1976 Montesa Cota 247T.  It's in decent shape other than the engine which was locked up tight when I got it.  I managed to free the piston with a judicious amount of beating with a hammer but now it gets tricky.  The cylinder appears to have been sealed to the cases with Yamabond.  I whacked it a couple of times with a rubber mallet but it's on there tight.  Any tips or tricks to getting the jug off without harm?

I also scored a couple other project bikes for down the road.  A 1973 Suzuki TS250 and a 1982 Maico 250.
Title: Re: Stuck Montesa cylinder
Post by: m in sc on February 09, 2026, 10:13:27 PM
heat gun. lots of heat.  no flame.... and thats awesome :vroom:
Title: Re: Stuck Montesa cylinder
Post by: quocle603 on February 10, 2026, 07:24:34 PM
Try Soaking in marvel mystery oil and tons of heat. Try the block of wood and hammer to break away the rust. I didnt have too much luck eith my rd so hammer and a socket. It destroyed the piston but I got it free!
Title: Re: Stuck Montesa cylinder
Post by: sav0r (CL MotoTech) on February 10, 2026, 09:35:41 PM
He got it. Crank is seized too.