The most expensive part in this assembly is the Oil Cooler Assy.
Parts such as the Oil Pump: Oil Cooler Assy, Nut, Flange(47x), Pin,dowel (137), Strainer, Oil are included in the Yfm350fww 1989 Big Bear Oil Pump parts fiche.
With four applications this Washer, Plate 3411117500 is the most specified part.