Abstract: An improved rotor-type carburetor for use with an internal combustion engine is provided which, in one embodiment, is adjustable to selectively vary its constant fuel-air ratio by axially moving an internal body portion thereof relative to the turbine rotor assembly of the carburetor. Alternatively, the constant fuel-air ratio of the carburetor may be altered simply by replacing such internal body portion with a differently configured one. Undesirable fuel delivery from the turbine rotor to the engine during turbine spin-down is significantly diminished through the use of an internal fuel reservoir structure, formed within the carburetor body, which functions to capture and retain unneeded fuel discharged from the rotor during turbine spin-down periods. During turbine spin-up periods (e.g., when the engine is being started) the reservoir-retained fuel is released into the engine's incoming air stream to hasten fuel delivery to the engiune during initial portions of turbine spin-up periods.

Abstract: An injection molded plastic turbine rotor for a rotor-type carburetor is assembled by simply pressing together upper and lower generally cylindrical sections. When joined in this manner the two sections form in the assembled rotor an internal circumferential seal between the two sections, and an internal passageway system which defines a centrifugal pump mechanism within the turbine rotor. In an alternate embodiment, the rotor includes a third plastic section which is captively retained within the rotor, between the upper and lower sections thereof, and is adapted to lockingly receive an end portion of a fuel supply tube inserted downwardly through a central opening formed through the upper section.

Abstract: The annulus (20) around the fuel feed stud (8) which seals the rotor (14) of this central injection device is connected to a stowage compartment (40) for intake air by way of a ball bearing (7). In the case of the impeller (31, 35) driven rotor (14), the stowage air pressure counteracts the leakage fuel pressure in the annulus (20). By .[.adapting.]. .Iadd.adopting .Iaddend.the width of the opening of the stowage compartment (40), the stowage air pressure is adjusted to be equal to or slightly higher than the leakage fuel pressure, so that no fuel can flow out of the annulus (20). .[.To enrich the fuel of the air-fuel mixture in the higher load range, a width of opening of the stowage compartment (40) is provided where the stowage air pressure at the corresponding RPM's becomes smaller than the leakage fuel pressure and the rotor (14) delivers additional fuel. .].