This is the locknut that secures the setting on the throttle cable adjuster for the Dellorto SHA10 and SHA12 carburetors.
This locknut is used on adjuster number 43 as well as cable elbow number 11 in the drawing.
Required quantity per carburetor: 1 + 1
This is item number 12 in the drawing.
Dellorto Part Number: 1691