In this schematic the "Circlip,piston Pin" is used most often.
Parts such as the Crankshaft: Seal,oil(47.3x60x6.5), Circlip,30mm, Crankshaft, Piston 0.50 are included in the Gs1000h 1980 (t) (e01 E02 E04 E17 E18 E21 E22 E24 E34) Crankshaft parts fiche.