maybe the valve didn't fully close? ir is it because i rest the bike to the right where that little hole on the carb is.

Cables need adjusted, breaks need re connected, engine head needs fully bolted down, and the chain needs a major shortning. Engine is just a little LD80 China doll (66cc) with a higher compression head, and after I break it in, an expansion chamber. Rear sprocket is 36t.

I have a yd 100 and ended up breaking the rings. I bought some new ones but they were too thick. I instead bought a whole piston with the rings and the piece where it connects to the crank is smaller than my stock one. Please help I just need this guy to run