think i got it, pulle dthe head and dam! about 4mm wide and from top to bottom theres a gouge in the cylinder wall. the pistin where the ring meets was messed up so seems i need a new top end which sucks because i just spent 140 on new piston/ring/gaskets, now i need to either bore it or get a stock replacement used. thinking either the gas/oil was wrong but it ran fine for a whole day with no problems or it overheated on me on a trail when i was going slow? or i installe dit wrong somehow