Grand Rapids Scooter's Crankshaft Assembly, Type-1 for 50cc 4-stroke QMB139 engines. Has 16 tooth oil pump drive gear.

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

Specifications:

• Stroke: 41.4mm
• 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
• Number of Teeth (oil pump drive gear): 16