a carburetor of the slide and metering rod type is characterized by the provision of a tapered metering rod for streamlining the flow of air from the inlet end of the carburetor around the metering rod to reduce turbulence and increase air velocity by compressing the air flow . the metering rod has a wedge configuration with the forward pointed edge thereof facing in the direction of the inlet end and the side walls thereof tapering outwardly and rearwardly from the forward edge .