NCY Gear Set (16*42); QMB139, CSC, Wolf, 50cc

NCY QMB139 upgear kit for your 50cc 4-strokes is finally here!  This kid is made specifically for big bored engines and increases your gear ratio by 24%.  This will allow you to maximize your big bore kit by increased top speed and a more usable rev range. You won't see much if any improved performance if you install these on a stock top end.