Ban Jing High Torque GY6 Starter Motor CM169-282. $104.99 Shipped in the US.

Ban Jing High Torque Starter motor for 150cc and 125cc GY6 4-stroke
**This Starter Motor is recommended for any GY6 with a Big Bore Kit or Stroker Big Bore Kit**

Bolt Hole Spacing: 78mm
Shaft Length: 22.5mm
Shaft Diameter: 11.5mm
Diameter (near o-ring): 30mm
Number of Splines: 9