NCY
NCY GY6 Upgear Kit - Increase Top Speed
Description
Fine-tune your GY6's final drive ratio with an NCY 14-tooth Counter Shaft Gear Wheel. Available in three driven gear options — 36, 37, or 38 teeth — this single gear change lets you shift the balance between top speed and off-the-line acceleration without splitting the cases. Fits both A-block (54mm) and B-block (57mm) GY6 engine families. ISO 9001 certified and made in Taiwan by NCY since 1997.
Choosing Your Gear Ratio
The stock GY6 150cc final drive is typically a 14?40 combination. Swapping the driven gear changes the ratio and shifts the power delivery:
| Gear Option | Ratio vs. Stock 14?40 | Effect |
|---|---|---|
| 14?36 | Shorter (numerically lower) | Higher top speed, reduced low-end torque and acceleration. Best for flat roads and top-speed builds. |
| 14?37 | Slightly shorter than stock | Balanced upgrade — modest top speed gain with minimal sacrifice in acceleration. Good all-around street tune. |
| 14?38 | Close to stock | Near-stock ratio with slightly improved top speed over a 40T gear. Ideal for mild tuning or replacing a worn gear. |
Tip: Going to a lower tooth count (36T) raises top speed but means your engine will be spinning closer to its rev limit at speed. Pair with a big bore kit or performance exhaust to make the most of the taller ratio. If you just want a mild bump in top speed without sacrificing rideability, the 37T or 38T is the safer choice.
Specifications
- Counter Shaft Teeth: 14
- Driven Gear Options: 36T, 37T, or 38T
- A-Block Fitment: 54mm stud spacing
- B-Block Fitment: 57mm stud spacing
- Origin: Made in Taiwan by NCY (ISO 9001)
Compatibility
Fits GY6 157QMJ-based 125cc, 150cc, and 169cc engines with the following engine codes:
| Engine Code | Engine Code | Engine Code | Engine Code |
|---|---|---|---|
| 157QMJ | 161QMK | 152QMI | 1P61QMK |
| YN1P57QMJ | 1P52FMI | 154FMI | JJ157QMJ |
| 1P57QMJ | BN157QMJ | BN161QMK-A | Other QMJ / QMK / QMI |
Don't see your engine code? If your engine code contains "QM" or "FM", this gear is likely compatible with your vehicle.
Performance upgrades are considered racing parts and are not covered by warranty. This product is intended for off-road use only and is not legal for use in California on pollution-controlled vehicles. Check local laws before installing.
Product Diagrams
Features
Specifications
Brand: NCY; Part number family: 1200-1059; Variant SKUs: 1200-1059 14X36, 1200-1059 14X37, 1200-1059 14X38; Type: Performance upgear pair; Shaft gear: 14 teeth; Gear options: 36, 37 or 38 teeth; Platform: Compatible GY6 125/150/169cc; A-block reference: 54 mm cylinder-stud spacing; B-block reference: 57 mm cylinder-stud spacing; Origin: Taiwan; Intended use: Off-road only
Model Fitments
Compatible GY6 125/150/169cc A-block and B-block gearbox configurations; engine-code references: 157QMJ, 161QMK, 152QMI, 1P61QMK, YN1P57QMJ, 1P52FMI, 154FMI, JJ157QMJ, 1P57QMJ, BN157QMJ, BN161QMK-A and matching QMJ/QMK/QMI applications; verify gearbox layout, shafts, bearings, splines and gear configuration
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Same day shipping for orders placed before 2PM (CST) M-F
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30-day return period on eligible items
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Flat-rate shipping for orders shipped to the 48 Contiguous United States.
