In this schematic the "Screw,cross 6x32" is used most often.
Some items from this specific schematic: Bolt,hex.,6x16, Screw Pan 6x55, Screw,cross 6x32, Oilseal,16x22x3.5.
The lowest price component in this Left Crankcase Cover parts-list fiche is the Bolt,hex., 6x16.