the gears are for YAMAHA motorcycle 125cc---scotter gears

This series of gears are used on scooter engines, it carries out slowdown
and transmission functions. Suitable for 125cc scooters made according to the
technical requirements for Yamaha models---including scotter gears

specifications:
1) Modal: 1.25 - 1.75mm
2) Material: alloy-carburized steel
3) Main processing: precision hot and cold forging, precision
machining and extrusion pressing
4) Heat treatment: carbonitriding, case depth 0.3~0.6mm
5) Good wear resistance and high strength
6) High precision and low noise

7) Main customer: GM, TRW, ZF, DANA, Ford, MAGNA, BorgWarner, HONDA, YAMAHA, SUZUKI, etc.