os max

I just got a pre owned nitro jato a few weeks back and the engine attached was a TRX 3.3 and the previous owner had broken the piston rod, he made sure I was aware and gave me a Discontinued OS Max 18 cvr nitro engine that has never been ran with it. How do I piece this thing together and should...

I have a OS max 12cv that you guys helped me free up I got it used my question is it looks like something is missing under head is there supposed to be a shim or something there. Does the head seat down into sleve or sit on top? This one is sitting on top of sleve.

Got it freed up thank all of you that helped

My OS max is stuck but it's not the piston I took sleeve out soaked internals in wd40 but won't break free it doesn't budge at all I am trying to turn it over with vice grips on tail shaft. It dosent have clutch bell on it and is out of vehicle locked up sitting for a few years. Help I'm a new...