the present invention provides a fuel system for an internal combustion engine powered by fuel that includes a fuel tank having a wall defining a volume . the fuel system also includes a pump that is disposed proximate the fuel tank and operatively connected to the volume . the fuel system further includes piping that is coupled to the pump and is operatively connected to the internal combustion engine . a pressure regulator with a self - contained valve assembly is disposed in at least one of the pump or the piping .