Abstract: An air rotor within the carburetor bore and rotated by air drawn into the bore during engine operation has extremely small diameter fuel jets associated therewith that inject fuel into the bore in counterflow relationship to the inrush of air, thereby markedly increasing atomization. In addition, the jets are directed to inject the fuel into the bore in a forward direction with respect to the direction of rotation of the rotor, hence propelling the fuel against the force of air in the bore to thereby further promote atomization. These features function independently and in cooperation with one another to increase engine operating efficiency and decrease the level of polluting emissions.