Abstract: An assembly being interposed between a carburetor and an intake manifold comprises three spacer plates and at least two screens for vaporizing the highest concentration of fuel and for passing unobstructed the highest concentration of air traveling therethrough. The top and bottom screens are separate and parallel and extend traversely across and are substantially perpendicular to the primary passageway formed by the aligned centrally located primary passageway openings in each spacer plate. The top screen covers approximately one-half the cross-sectional area of the primary passageway opening. The bottom screen covers approximately one-third the cross-sectional area of the primary passageway opening, and both screens are situated and positioned directly below the back side of the carburetor's throttle valve.