NCY Gear Set (17*41); 139QMB, CSC, Wolf, 50cc polini performance variator kit Versatile Mounting: Great for roll

Versatile Mounting: Great for roll bags

see the compatibility table below to ensure this works with your bike

This kit is a direct performance upgrade for 50cc and 80cc (139QMB/GY6) engines:

5" W x 4" H

Comprehensive Model Fitment List

NCY Gear Set (17*41); 139QMB, CSC, Wolf, 50cc polini performance variator kit Versatile Mounting: Great for rollNCY 139QMB upgear kit for your 50cc 4 strokes is finally here! This kit is made specifically for 88cc big bored engines and increases your gear ratio by 30%. This is the mother of all upgears for the 50cc 139QMB scoots. Only effective if you have a full blown 88cc kit with a big valve head, and stroker crank.