The most reasonably priced component used on the Xl600r 1985 (f) E-10 Crankcase is the Bolt,hex 6x12.
This schematic depicts all components used in the Xl600r 1985 (f) E-10 Crankcase partslist.
On this parts fiche the Bolt,flg.soc,6x32 is the most specified component.