The most expensive part in this assembly is the Camshaft.
thirty-five components are listed in the schematic for this Dr500r 1986 (g) Cam Shaft - Valve .
A sample from the products for the Cam Shaft - Valve include: Shaft,valve Rocker Arm, Gasket(5.8x13x1.2) (nas), Spring Set,valve, Nut,adjusting Screw.