This NCY main jet (#128) works with 139QMB and GY6 bikes and nearly any 5mm main jet slot CVK carburetor.
Jetting is something that takes trial and error. See our blog of jetting instructions for more info.
Original Parts For Scooters SKU 114-35-128
Specifications:
Compatibility:
139QMB-based 50cc / 80cc engines with the following engine codes:
157QMJ-based 125cc / 150cc / 169cc engines with the following engine codes:
Don't see your engine listed? If the engine code includes "QM" or "FM" and you're running a 5mm main jet slot CVK carburetor, this product is compatible with your vehicle.
About NCY: NCY is the aftermarket performance parts leader for most popular scooter brands including Honda, Yamaha, Genuine, Vespa, SYM, Lance, KYMCO, and GY6 / QMB powered scooters. Made in Taiwan with strict quality standards since 1997, NCY is ISO 9001 certified.
Made in Taiwan.
