Abstract: An improved carburetor (20) for delivering one combustible fuel and a liquid, or two combustible fuels from separate reservoirs (50), (500), to the central portion of a hollow spray bar (98) for discharge into carburetor venturi (30) includes substantially closed metering chambers (90), (508) disposed in fuel flow communication from the reservoirs and suspended from opposite ends of spray bar (98). Fuels from metering chambers (90), (500) travel through variable width grooves (154), (548) formed in arcuate metering inserts (148), (544) into the lower end portion of corresponding metering arms (92), (540) and then into the hollow interior of spray bar (98).