Custom Builds and Performance Parts

Jasil Top Racing 18/50 Gear Set For QMB139

There is only 1 item left in stock.
Jasil Top Racing 18/50 Gear Set for 50cc QMB139 4-Stroke Engines. +17% Gear Ratio for increased top speed. It is recommended this gear set be used after installing a big bore cylinder kit. A stock engine will not have enough power to make use of a taller gear set.

Made in Portugal! No press required, just drop in and go!
  • 18/50 Gear Set (2.78 to 1 ratio)
  • No pressing of gears required! Swap in place of your stock gears.
  • QMB139 50cc/49cc