In this schematic the "Acrew-pan Head,5x14" is used most often.
Some items from this specific schematic: Lever-grip,clutch, Boot,throttle Case,rh, Nut,cable Adjust Nut, Handle.
The most reasonably priced component used on the Kdx250-b1 Kdx250 1981 Usa California Canada Handlebar ('82 Kdx250-b2) is the Screw-pan-cros.