Parts such as the Camshaft: B/brg Rad N/com, Spring,valve Inne, B/brg Rad N/com, Valve,ex. are included in the Cn250 Helix 1986 (g) Usa Camshaft parts fiche.
The most reasonably priced component used on the Cn250 Helix 1986 (g) Usa Camshaft is the Circlip,ex,15.
In this schematic the "Cotter,valve" is used most often.