Realistically, the quickest and surest way to deal with it is to drain the gas from the reservoir, usually by backing out one of the lower corner screws. Then, unscrew the 4 screws and pull off the float reservoir. Be careful undoing the screws cause there are small washers that tend to stick to the resv. rather than coming off with the screw! You can remove the needle and blow out the seat area with compressed air (a can of compressed air used for cleaning computer keyboards works well). With the needle reinstalled, you hold the part horizonal and measure the drop when the needle is fully closed. There is a spec for this distance, but I don't know what it is. In the old days, you bent the tab on the float to adjust the float level, but with the new double pumpers, the adjustment is different. On my speed demon carb, you have a sight class window in the side of the resrv. and it has level markings on it. You just turn the adjusting bolt on top of the reservoir and watch the gas level move. Good luck!!!!