Big Bore kit - 50mm/100cc Large Valve - for 49cc,139QMB

Upgrade your 50cc scooter to reach higher speeds and improved acceleration with Pitmoto's Big Bore Kit - 50mm/100cc. This comprehensive kit includes everything you need for a seamless installation, including the A9 Cam and Rocker Arms assembly. No more guessing games with valve measurements, as we have thoughtfully included the rocker arms assembly to ensure compatibility.

The cylinder has a 50mm bore, giving you 100cc of power. The intake valve diameter is 23mm, and the exhaust valve diameter is 20mm.

With fast shipping and hassle-free returns, Pitmoto is the brand you can trust for high-quality scooter upgrades.

Please note that this kit is not recommended for inexperienced installers and should be installed by an experienced scooter or motorcycle mechanic. The valves will require adjusting, and the timing must be set correctly. Failure to correctly set the timing can result in catastrophic engine damage.