On this parts fiche the Ball(71f) is the most specified component.
Parts such as the Governor: Washer, Plate(39x), Collar (5x4), Oil Seal (8x12x3-371), Screw,pan Head(1rw are included in the Yz125 2003 5un2 England 1b5un-100e1 Governor parts fiche.
The Governor is made up of components including this Push Rod Assy which is the most expensive.