Parts such as the Magneto: Coil Assembly,ignition, Clamp L:35, Stator Assembly, Lock Washer are included in the Jr50 1978 (c) Usa (e03) Magneto parts fiche.
With two applications this Screw 4x25 is the most specified part.
The most reasonably priced component used on the Jr50 1978 (c) Usa (e03) Magneto is the Screw.
