It sounds like the needle, which is attached to the float is stuck open, or missing.I am going to guess and say there should be a float, a needle valve, a pin to hold them together, a few screws to hold the bowl over these things.i would guess to say its got a low speed and a high speed adjustment screw. Set em at least a turn out each to start it. that is probably about all the parts . try polishihg the needle/and seat so that it is not sticking open.