I am trying to help my son. We are baffled. This old 50cc Eton has sat form some time. Compression was low and the ring gap was very large. Replaced the cylinder, piston and ring. With the carb remowed and the oil mix resovoir disconnected this thing is blowing a mist of fuel out of the cylinder. If we install the carb and the fuel line the new spark plug becomes saturated with fuel. Any ideas would be greatly appreciated, Thanks Gary

 

Did you remember to add the head gasket? Could be pressing out of the head/join.
Where in the head is it coming from?
Could it be coming from the spark plug connection? May not be in right.

 

Id guess the crank case was/is full of gas and your pumping it out. Wait till it stops spraying gas to attach the carb and exhaust.. If it did it after installing the carb Id think your needle/seat is dirty and flooding the engine with gas.