Victa said this below on the G2 Patent. For many years-speed governing in such engines has been achieved by positioning in the path of the cooling air stream a light-weight flag-like member,the vane of which is- displaced by the air -flow to rotate its spindle for closing down the throttle control valve as the engine speed increases.
The first G2 carby obviously wasn't working correctly so the 2 amendments (flag and spring) were made to fix the problem until the G3 came out.
