Abstract: A carburetor incorporating an air passage, and a fuel passage, and a rotating barrel, the rotating barrel being arranged between the air passage and the fuel passage so that a first portion of its surface is exposed to the air passage, and a second portion of its surface is exposed to the fuel passage. The rotation of the barrel transfers fuel from fuel passage to the air passage via an indent feature, the proportion of that indent feature that is exposed to the air or fuel passage being varied to meter the amount of fuel transferred.