“Rear Clutch Pulley Assembly for GY6 125cc / 150cc Scooters – CVT Transmission / Polea y Clutch Trasero Motonetas GY6 125cc 150cc”📐
 Dimensions 
(Rear Pulley + Clutch Assembly)From the diagrams you uploaded:Clutch Bell (Outer Cover)
:Outside Diameter: 137 mm
Inner Diameter (spline area): 15 mm
Bell Width: 125 mm
Rear Pulley Assembly (Clutch + Pulley):Outer Pulley Diameter: 142 mm
Pulley Face Width: 115 mmCenter Hole (input shaft): 22 mm
Clutch Shoes (Swing Size):Shoe Contact Diameter: 115 mm
Center Hole: 24 mm 
(boss)Inner Fit Section: 28 mm
Height across pads: 66 mm