Take the carb off. Remove the two screws that hold the float bowl on. Check the float to see if it is full of fuel. If so, replace it. If not look at the brass u shaped lever that the float pushes against. It is held in place with a pin. Push the pin out and remove the arm. You will find the inlet needle and seat. There is likely a piece of debris preventing the needle from closing on the seat and blocking the flow of fuel. Clean well with carb cleaner and reassemble.