Re: how much compression can these things take?
The usual tricks apply as to any 2-stroke engine.
I think it will help going to 8mm head studs if you intend to machine the top of the cylinder and the cylinder head.
In reality, these engines are underpowered for their capacity, quite possibly to deliberately keep them under 2 horsepower.
The biggest issue seems to be the factory balancing of the crankshaft, not to mention it's inadequate design, and from there, the intake and exhaust side of things.
I know the company Puch makes a lot of good parts and the 50cc cylinder almost fits straight onto the cases, with some modification.
Last edited by Fabian; 06-02-2010 at 11:06 AM.