GY6 150 Starter Motor Reduction Gear and Shaft

If your starter whirs, grinds, or clicks but the engine won't turn over, check the reduction gear before you buy a new starter. This stepped two-stage gear sits between the starter motor and the starter clutch gear. Every electric start runs through it, so worn or chipped teeth are common on high-mileage GY6 engines, and even more common on big-bore builds running a high-torque starter.

This kit includes the reduction gear and its shaft. Install them together so you aren't running a fresh gear on a worn shaft.

Fitment: GY6 125cc / 150cc four-stroke engines, including the 152QMI and 157QMJ families (YN1P57QMJ, JJ157QMJ, 1P57QMJ, BN157QMJ). Also used on many 161QMK / 1P61QMK engines. Found in scooters, go-karts, buggies, and UTVs from Baja, Hammerhead, Kazuma, Roketa, SunL, TaoTao, and others, plus the Polaris RZR 170.

Compare your original gear's tooth count, bore, and overall height before ordering. GY6 clones vary.