Grand Rapids Scooter's Hoca 44mm Stroker Crankshaft Assembly for 50cc 4-stroke QMB139 engines.

Supported Models: Bintelli, Tao Tao, Peace Sports, Wolf, Schwinn, Puma, SYM, Alliance, Motorino, and Kymco.

Specifications: 

• Overall Length: 247mm
• Thread Size (tapered side): M10x1.25
• Thread Size (spline side): M12x1.25
• Bearing Outer Diameter (tapered side): 42mm
• Bearing Outer Diameter (spline side): 47mm
• Number of Splines: 26
• Connecting Rod Inner Diameter: 13mm

• Number of Teeth (oil pump drive gear): 16