Hallo!
You would better buy a new ,more modern, engine!!!
The OS .40P engine is a pylonversion of the OS .40 R/C engine made in the middle of the sixties,it has dual ball bearings and is a sideexhaust engine, not schnurle ported but a cross flow engine with a cam on top of the piston to direct the gases inside the combustionchamber.
If any engine has been stored this long (since-68)
I would definitly buy new ballbearings for it. But since your engine lacks the silencer and is not as good running as a modern engine I would let it rest in peace.....Because it will never function as good as a modern engine will....and spare parts is no were to be found!


Best regards!
Jan Karlsson
Sweden