The Ruima Cast Iron Cylinder is just what your GY6 50/139QMB scooter needs to give it that extra power its been lacking. This Ruima big bore kit comes packed with perfromance benefits. Upgrading your cylinder on a 4 stroke motor is the best place to start for increasing power. Ruima makes a high quality, reliable performance cylinder that you can rely on.

The 139QMB engine is one of the most popular engines used today. Like most 50cc 4 stroke engines many are starved for power, and can really use an upgrade. The install is pretty straight forward.

This kit comes with cylinder, piston, rings and gaskets. This kit may work with your stock head or you can upgrade to the Ruima 52mm performance head for even more power gains.

This part fits:
139QMB
Many Chinese 50cc 4t scooters.
Kymco
Most

Zuma 125