This engine is a real gold for builder
In stock form it can run a few thousand miles without engine rebuild. However, engineering inperfections and cheep design cause some problems when you run it on its edge. Electric starter can't handle my 14 bar (200 psi) compression. I can barely start it this way. Kick starter is designed to be used on emergencies only, because of that whole kick starter assembly wears down quickly. That is true that you can find a lot of performance parts really cheap.
I will post more detailed information and pictures on weekend when I get home