Carburetor insert apparatus

In a carburetor system for an internal combustion engine, which engine includes a carburetor for supplying a mixture of fuel and air to said engine, the combination therewith of an insert situated after said carburetor and positioned between the carburetor and the engine, said insert comprising a cup-like cylindrical member having an open top surrounded by a peripheral flange, a major sidewall surface having located thereon regularly spaced rectangular apertures, with said apertures occupying a substantial portion of the total area of said surface, a bottom surface having a plurality of circular apertures each of a relatively small diameter and arranged in concentric circles about a central aperture with said circular apertures located about said central aperture in at least four concentric circular patterns with the apertures in the third circular pattern located between the apertures in the second and fourth pattern, first and second circular screen members inserted within the hollows of said insert and overlying said bottom surface with said screen members being moveable with respect to one another and with respect to said bottom surface and a cylindrical screen member having an opened top and an opened bottom inserted within the hollow of said insert and overlying said rectangular apertures.