Vespa Cosa Clutch Sprocket 21 Tooth (67-68 Primary Gear) PX, T5, Cosa
This sprocket fits on the inside of the clutch. This Clutch Sprocket meshes with the Primary drive, and this in turn drives the primary drive which is attached to the input shaft.
PX125, PX150, T5, PX200 differences:
PX125 ?? PRIMARY DRIVE (67/68) STANDARD TOOTH GEAR 20
PX150 ?? PRIMARY DRIVE (67/68) STANDARD TOOTH GEAR 20
PX200 ?? PRIMARY DRIVE (64/65) STANDARD TOOTH GEAR 23
T5 ?? PRIMARY DRIVE (67/68) STANDARD TOOTH GEAR 21