Rotary carburetor

In the carburetor (1) according to the present invention, three downstream body passages (10b, 11b, 12b) in the body (2) communicate with three valve passages (20, 21, 22) in the valve element (4), and the valve element (4) rotates between a closed position and an opened position. The carburetor (1) is one-bore type carburetor in which the body passages (10b, 11b, 12b) and the valve passages (20, 21, and 22) are respectively partitioned with the body partitions (14, 15) and the valve partitions (24, 25). When rotating the valve element (4) from the closed position to the opened position, the second body passage (11b) and the second valve passage (21) for mixture start to communicate in advance than the first and third body passages (10b, 12b) and the first and third valve passages (20, 22) for air.