yamaha aerox 50?

hi.my yq50 started playing up .felt like starvation of petrol.i have cleaned the carb.i have put new piston ,rings and head on it.put new exhaust and spark plug.the bike now turns over but will not start. i have a spark,when i take spark plug out it turns over really fast when i put back in turns over bit slower.so think compression is there.could it be the auto choke? i did take it into a shop but they charged me £90 for 2 hours labour.apparently theyu done the same as i did already.cleaned the carb> could it bee the reeds .they look ok and are flat.please help.