Dr. Pulley HiT Clutch (22spline, 107mm) 139QMB, Kymco drpulley The perfect upgrade for most

The perfect upgrade for most 4T 139QMB/GY6 50 scooters

Broader gear ratio — belt sits lower at start-up and higher at top speed than OEM rollers allow

They have everything you could want out of a performance clutch

and 2T Minarelli bikes running NCY's 47mm Cylinder Kit

JJ157QMJ / BN157QMJ / YN1P57QMJ

Dr. Pulley HiT Clutch (22spline, 107mm) 139QMB, Kymco drpulley The perfect upgrade for mostDr. Pulley high performance HiT clutch for 50cc 139QMB engines. Original Parts For Scooters SKU 169 223, SKU 169 224 Get quicker, harder launches and positive engagement with these HiT Clutches. They have everything you could want out of a performance clutch, from fantastic machining and craftsmanship to great feel and response. Specifications: Inner Diameter (bell): 107mm Overall Height (bell): 34mm Number of Splines (clutch bell): 22 60 Degree