Abstract: The thermal stability of jet fuel sweetened by oxidation is improved by washing the sweetened fuel with strong aqueous caustic.

Abstract: A variable venturi-type carburetor comprising a hollow cylindrical casing and a suction piston which is movable in the casing. The casing has a support pipe extending along the axis of the suction piston. The suction piston has a piston rod which is inserted into the support pipe. A bearing sleeve, equipped with a plurality of balls, is inserted between the piston rod and the support pipe. The bearing sleeve has a plurality of connecting grooves formed on the outer circumferential wall of the sleeve and extending in the axial direction of the sleeve over the entire length thereof.