NCY Gear Set (16*42); 139QMB, CSC, Wolf, 50cc
NCY Gear Set (16*42); 139QMB, CSC, Wolf, 50cc
$68.72
10 in stock
*Note: Free shipping to U.S. mainland (excludes AK, HI, and territories)
Orders placed by 1pm EST on weekdays ship the same day.
Product Details
DESCRIPTION: NCY 139QMB 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.
139QMB ENGINES: 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.
Compatibility / Fitment
Use the fitment details below to confirm this part matches your scooter before ordering.
- Engine Size: 50cc
- Engine Code: 139QMB
- Fitment Notes: Big Bore, Performance
Fitment Guide: This compatibility information is based on manufacturer and supplier data. Listed models are common known applications and may not include every compatible scooter. If your scooter has multiple versions or production changes, confirm the correct match before ordering. Check photos, measurements, original part numbers, engine code, model, and related fitment information whenever possible.
Common Fitment Questions
Q: Will this fit a 139QMB engine?
A: This SKU is listed as compatible with 139QMB engine-code fitment. Always compare your original part and scooter details before ordering.
Q: Is this for 50cc scooters?
A: This SKU is listed with 50cc engine-size fitment. Confirm exact model, year, and part style before ordering.
Additional information
| Weight | 2 lbs |
|---|---|
| Dimensions | 6 × 4 × 2.1 in |
NCY 16x42 upgear kit for 139QMB (GY6 50cc) 4-stroke engines. Increases the final drive gear ratio by approximately 24%, raising top speed and broadening the usable rev range. Designed for big-bore builds — minimal benefit on a stock top end.
Includes 16-tooth countershaft gear and 42-tooth final drive gear.
Key Features
- 16x42 gear ratio — ~24% taller than stock
- Increases top speed and usable rev range
- Designed for big-bore 50cc builds
- NCY-branded machined steel gears
- Fits QMB139 / GY6 50cc 4-stroke engines
| Countershaft Gear | 16 teeth |
|---|---|
| Final Drive Gear | 42 teeth |
| Ratio Change | ~24% taller than stock |
| Engine | QMB139 / GY6 50cc 4-stroke |
| Brand | NCY |
Fitment
Fits any 139QMB / GY6 50cc 4-stroke scooter. Compatible with most Chinese-manufactured 50cc scooters, including CSC, Wolf, Peace Sports, Tao Tao, Icebear, Jonway, Bintelli, BMS, SSR Motorsports, SunL, and many more.
Performance part — not for use on pollution-controlled vehicles or public roads. Check local laws before installing.
