This NCY 81cc Aluminum Performance Cylinder Head is compatible with 50cc 139QMB engines. Use this cylinder head with NCY's 81mm Cylinder Kit to give your bike the power to handle today's city traffic.

Specifications:

• Cylinder Head Stud Space: 50mm / H: 60mm / Intake Port: 24mm / Exhaust Port: 22mm
• Valves: 21.5x64mm Intake / 19x64mm Exhaust / Stem: 5mm / (w/intake valves) H: 66.1<67.3mm
• Valve stem length: 64mm
• 6mm Intake Threads
• 6mm Exhaust Threads

NOTE: Most 139QMB stock cylinder heads have valves that are 69mm high and use a 69mm rocker arm. This cylinder head has 64mm high valves and will only work with a 64mm rocker arm. Please check the stock valve stem height before ordering.

Compatibility:

139QMB-based 50cc / 80cc engines with the following engine codes:

Don't see your engine listed? If the engine code includes "QM" or "FM" and you've ensured the valve height and rocker arm on your bike are 64mm, 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.

This product is intended for off-road use only.

This product is not intended for use on public roads or land.

This product is not legal for use in California on pollution-controlled vehicles. Check local laws before installing.

*Performance upgrades are considered racing parts and are not covered by warranty.