GY6B Clutch Assembly with Bell Clutch Assembly with Bell for 150cc GY6B 4-stroke ZNEN engines commonly found in Lance Phoenix, Flyscooters Cadenza, ZNEN ZN150T-18, Xingyue ITA-150, Motorino Cassini, CMS Prodigy, BMS Pathfinder and many more. Clutch Bell Inner Diameter: 125mm Clutch Bell Outer Diameter: 136mmNumber of Splines (clutch bell): 19Splined Inner Diameter (peak to peak): 13.6mmSplined Inner Diameter (valley to valley): 15mm Outer Diameter (pulley): 155mm