It has something stuck in the needle and seat as dirt as pull the fuel bowl of the bottom of the carbie and pull then pull the float out by pulling the pin on the float and becareful when you do this as not lose the the needle put back together and should start run cheers

The float in carb is not shutting off suply when the carb chamber full so the fuel is constanly filling the carb this is known as flooding carb either the float needle is mis aligned with the needles seat or theres a object or deris the seat stopping it fully closing off the fuel flow cheak thease the float may also damaged and filling up with fuel this stops it riseing and again the carb floods