Check out any of the twenty-nine Carburetor Assy. 81-82 components enlisted.
The Screw-wash. 5x12 is the most widely applied product in the CB650 1981 (B) USA CARBURETOR ASSY. 81-82 ( eight times ).
The component with the lowest price in the CARBURETOR ASSY. 81-82 schematic is the Clip, Tube.