There are two gaskets in the Walbro..One on the pump diaphragm side goes on top of the pumo diaphragm, the one with no metal center..Other side has a gasket under the metering diaphragm, metal center, then the cover...The carb will NOT function correctly if either of the diaphragms is not positioned correctly..PERIOD,,,You can dink around all day long with changing needles and lever height,,,The engine MIGHT run, but not right...Like Rush says, "do not doubt me"