Rotary carburetor

Abstract

A versatile rotary carburetor has an idle adjustment needle, a high speed adjustment needle, and preferably an air bypass screw which are substantially parallel to one another and are axially exposed for adjustment in a substantially common direction. Preferably a cammed rotary throttle valve is seated in a body of the carburetor for rotation about and axial movement along an axis. The rotary throttle valve intersects a mixing passage in the body, and carries a through-bore that variably generally aligns to the mixing passage upon rotation of the throttle valve. The throttle valve projects axially through an external surface of the body and threadably receives the idle adjustment needle oriented concentrically to the axis. A primary fuel feed tube disposed concentrically to the axis projects into the through-bore to receive the idle adjustment needle at an open distal end which variably obstructs an orifice in a cylindrical wall of the tube that generally communicates with the through-bore for delivering liquid fuel to the mixing passage. The high speed adjustment needle is preferably threaded to the body for adjustably intersecting and obstructing a fuel passage in the body that flows liquid fuel to the fuel feed tube for the flow of liquid fuel. Preferably, the air bypass screw threads into the body for adjustably intersecting and obstructing an air bypass passage in the body communicating at both ends with the mixing passage for generally bypassing the rotary throttle valve when in an idle position.