Abstract: A system for introducing fuel into a fuel burning chamber or area wherein an extremely lean mixture of air and fuel is directed through a catalyst into a blending chamber and is discharged from the blending chamber through a second catalyst into an ignition or burning chamber. The system may be used efficiently with low grade or heavier fuel. When using the low grade or heavier fuels, it is desirable to heat or vaporize the fuel prior to the introduction thereof into an atomizer or the catalyst and substantially complete combustion occurs in the ignition or burning chamber for substantially eliminating the emission of unburned hydrocarbons, thus not only conserving fuel but also reducing air pollution.