I believe all walbro carbs have a built-in regulator. if you raise the tank above the carb with engine off and fuel flows into the carb, then this is wrong. the regulator is stuck open. take the carb apart and look at the regulator assembly. it is a lever (like a teeter-totter) whereby one end of the lever pulls a small needle out of a hole. there is a spring that forces the needle back in the hole. this lever as actuated by a diaphragm that is sucked down by venturi suction in the throat of the carb. With the motor off, the spring should force the needle into the hole, sealing off the fuel flow.