Carburetor

Claim 1

A carburetor comprising an intake passage, a main nozzle opening to the intake passage, a float chamber, a main fuel passage for connecting said main nozzle with said float chamber, a slow fuel nozzle opening to said intake passage, a slow fuel passage for connecting said slow fuel nozzle with said main fuel passage, a change-over valve interposed between said main fuel passage and said slow fuel passage, said change-over valve being provided with main jet ports of different diameters and slow jet ports of different diameters for changing the degree of communications between said main fuel passage and said float chamber and between said slow fuel passage and said main fuel passage, a stationary supporting sleeve having groups of apertures formed in the peripheral wall thereof and an annular chamber surrounding said peripheral wall, said annular chamber communicating with said intake passage upstream of said main nozzle, and an air bleed pipe rotatably fitted in said supporting sleeve and having said main fuel passage defined therein, said air bleed pipe being provided in its peripheral wall with a plurality of groups of air bleed ports of different air bleed characteristics, said air bleed ports being adapted to be placed in selective communication with said groups of apertures of said supporting sleeve in accordance with the rotational position of said air bleed pipe.