NCY Compression Spring (GY6), 1500 rpm
NCY Compression Spring (GY6), 1500 rpm
$27.60
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: If the engine code includes “QM” or “FM”, this product is compatible with your vehicle.Mechanic’s Notes:Compression springs (also known as contra springs) do two things. First, they provide lateral pressure on the drive belt to prevent belt slip. Second, they determine the rate at which the CVT transmission changes from lower to higher gear ratios.For optimum acceleration, match the clutch pulley transition from lower to higher gear to the peak power of your scooter.For example: If your scooter creates peak power at 7500 rpm and your current compression spring is transitioning to fully open at 6000 engine rpm, your acceleration will be slower than optimal. Increasing the stiffness of your compression spring will increase the engine RPM required to achieve the highest gear ratio in this example.Stiffer Compression Spring = More Belt Tension & Pressure + Higher RPM transitionSofter Compression Spring = Less Belt Tension & Pressure + Lower RPM transitionLooking for more performance upgrades? This spring is also available as part of ourStage 1 GY6 150 Performance Kit!About NCY:NCY is the aftermarket performance parts leader for most popular scooter brands including Honda, Yamaha, Genuine, Vespa, SYM, Lance, KYMCO, and GY6 / QMB powered scooters. Made in Taiwan with strict quality standards since 1997, NCY is ISO 9001 certified.Made in Taiwan*Performance upgrades are considered racing parts and are not covered by warranty.
SPECIFICATIONS: Wire Diameter: 4.2mmInner Diameter: 48.5mm
COMPATIBILITY: GY6 engines139QMB-based 50cc / 80cc engines with the following engine codes:139QMA139QMB1P39QMB1P39QMA-2YN139QMBJJ1P39QMB139FMA-2BD1P39QMBBN139QMB147QMDOther QMA modelsOther QMB models157QMJ-based 125cc / 150cc / 169cc engines with the following engine codes:157QMJ161QMK152QMI1P61QMKYN1P57QMJ1P52FMI154FMIJJ157QMJ1P57QMJBN157QMJBN161QMK-AOther QMJ, QMK, and QMI modelsDon’t see your engine listed? If the engine code includes “QM” or “FM”, this product is compatible with your vehicle.Mechanic’s Notes:Compression springs (also known as contra springs) do two things. First, they provide lateral pressure on the drive belt to prevent belt slip. Second, they determine the rate at which the CVT transmission changes from lower to higher gear ratios.For optimum acceleration, match the clutch pulley transition from lower to higher gear to the peak power of your scooter.For example: If your scooter creates peak power at 7500 rpm and your current compression spring is transitioning to fully open at 6000 engine rpm, your acceleration will be slower than optimal. Increasing the stiffness of your compression spring will increase the engine RPM required to achieve the highest gear ratio in this example.Stiffer Compression Spring = More Belt Tension & Pressure + Higher RPM transitionSofter Compression Spring = Less Belt Tension & Pressure + Lower RPM transitionLooking for more performance upgrades? This spring is also available as part of ourStage 1 GY6 150 Performance Kit!About NCY:NCY is the aftermarket performance parts leader for most popular scooter brands including Honda, Yamaha, Genuine, Vespa, SYM, Lance, KYMCO, and GY6 / QMB powered scooters. Made in Taiwan with strict quality standards since 1997, NCY is ISO 9001 certified.Made in Taiwan*Performance upgrades are considered racing parts and are not covered by warranty.
139QMB ENGINES: based 50cc / 80cc engines with the following engine codes:139QMA139QMB1P39QMB1P39QMA-2YN139QMBJJ1P39QMB139FMA-2BD1P39QMBBN139QMB147QMDOther QMA modelsOther QMB models157QMJ-based 125cc / 150cc / 169cc engines with the following engine codes:157QMJ161QMK152QMI1P61QMKYN1P57QMJ1P52FMI154FMIJJ157QMJ1P57QMJBN157QMJBN161QMK-AOther QMJ, QMK, and QMI modelsDon’t see your engine listed? If the engine code includes “QM” or “FM”, this product is compatible with your vehicle.Mechanic’s Notes:Compression springs (also known as contra springs) do two things. First, they provide lateral pressure on the drive belt to prevent belt slip. Second, they determine the rate at which the CVT transmission changes from lower to higher gear ratios.For optimum acceleration, match the clutch pulley transition from lower to higher gear to the peak power of your scooter.For example: If your scooter creates peak power at 7500 rpm and your current compression spring is transitioning to fully open at 6000 engine rpm, your acceleration will be slower than optimal. Increasing the stiffness of your compression spring will increase the engine RPM required to achieve the highest gear ratio in this example.Stiffer Compression Spring = More Belt Tension & Pressure + Higher RPM transitionSofter Compression Spring = Less Belt Tension & Pressure + Lower RPM transitionLooking for more performance upgrades? This spring is also available as part of ourStage 1 GY6 150 Performance Kit!About NCY:NCY is the aftermarket performance parts leader for most popular scooter brands including Honda, Yamaha, Genuine, Vespa, SYM, Lance, KYMCO, and GY6 / QMB powered scooters. Made in Taiwan with strict quality standards since 1997, NCY is ISO 9001 certified.Made in Taiwan*Performance upgrades are considered racing parts and are not covered by warranty.
157QMJ ENGINES: based 125cc / 150cc / 169cc engines with the following engine codes:157QMJ161QMK152QMI1P61QMKYN1P57QMJ1P52FMI154FMIJJ157QMJ1P57QMJBN157QMJBN161QMK-AOther QMJ, QMK, and QMI modelsDon’t see your engine listed? If the engine code includes “QM” or “FM”, this product is compatible with your vehicle.Mechanic’s Notes:Compression springs (also known as contra springs) do two things. First, they provide lateral pressure on the drive belt to prevent belt slip. Second, they determine the rate at which the CVT transmission changes from lower to higher gear ratios.For optimum acceleration, match the clutch pulley transition from lower to higher gear to the peak power of your scooter.For example: If your scooter creates peak power at 7500 rpm and your current compression spring is transitioning to fully open at 6000 engine rpm, your acceleration will be slower than optimal. Increasing the stiffness of your compression spring will increase the engine RPM required to achieve the highest gear ratio in this example.Stiffer Compression Spring = More Belt Tension & Pressure + Higher RPM transitionSofter Compression Spring = Less Belt Tension & Pressure + Lower RPM transitionLooking for more performance upgrades? This spring is also available as part of ourStage 1 GY6 150 Performance Kit!About NCY:NCY is the aftermarket performance parts leader for most popular scooter brands including Honda, Yamaha, Genuine, Vespa, SYM, Lance, KYMCO, and GY6 / QMB powered scooters. Made in Taiwan with strict quality standards since 1997, NCY is ISO 9001 certified.Made in Taiwan*Performance upgrades are considered racing parts and are not covered by warranty.
NOTE: s:Compression springs (also known as contra springs) do two things. First, they provide lateral pressure on the drive belt to prevent belt slip. Second, they determine the rate at which the CVT transmission changes from lower to higher gear ratios.For optimum acceleration, match the clutch pulley transition from lower to higher gear to the peak power of your scooter.For example: If your scooter creates peak power at 7500 rpm and your current compression spring is transitioning to fully open at 6000 engine rpm, your acceleration will be slower than optimal. Increasing the stiffness of your compression spring will increase the engine RPM required to achieve the highest gear ratio in this example.Stiffer Compression Spring = More Belt Tension & Pressure + Higher RPM transitionSofter Compression Spring = Less Belt Tension & Pressure + Lower RPM transitionLooking for more performance upgrades? This spring is also available as part of ourStage 1 GY6 150 Performance Kit!About NCY:NCY is the aftermarket performance parts leader for most popular scooter brands including Honda, Yamaha, Genuine, Vespa, SYM, Lance, KYMCO, and GY6 / QMB powered scooters. Made in Taiwan with strict quality standards since 1997, NCY is ISO 9001 certified.Made in Taiwan*Performance upgrades are considered racing parts and are not covered by warranty.
Compatibility / Fitment
Use the fitment details below to confirm this part matches your scooter before ordering.
- Engine Size: 50cc, 80cc, 125cc, 150cc, GY6
- Engine Code: 139QMB, 157QMJ
- Fitment Notes: Performance, CVT, Auto Transmission
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 | 0.3 lbs |
|---|---|
| Dimensions | 6 × 2.5 × 2.5 in |
| Condition | New |
|---|
Fine-tune your CVT transmission's shift point and eliminate belt slip with the NCY 1500 RPM Contra / Compression Spring for GY6 engines. Engineered for the rear clutch pulley, this performance spring is a direct upgrade for riders looking to optimize acceleration on 125cc, 150cc, 169cc, and 171cc GY6-based scooters.
Key Features
- Prevents belt slip by increasing lateral pressure on the drive belt
- Raises CVT shift point for optimized acceleration at higher RPM
- 1500 RPM rating — stiffer than stock for performance-oriented tuning
- ISO 9001 certified manufacturing
- Made in Taiwan
- Wire Diameter: 4.2mm
- Inner Diameter: 48.5mm
- Length: 154.0mm
- RPM Rating: 1500 RPM
Fits 157QMJ-based 125cc / 150cc / 169cc / 171cc GY6 engines with the following engine codes:
| 157QMJ | 161QMK | 152QMI | 1P61QMK |
| YN1P57QMJ | 1P52FMI | 154FMI | JJ157QMJ |
| 1P57QMJ | BN157QMJ | BN161QMK-A | Other QMJ, QMK & QMI models |
Mechanic's Notes
Compression springs (also called contra springs) serve two functions: they apply lateral pressure on the drive belt to prevent slip, and they control the RPM at which the CVT transitions from lower to higher gear ratios.
For optimum acceleration, match the clutch pulley transition RPM to your engine's peak power band. If your engine peaks at 7500 RPM but your spring transitions at 6000 RPM, you're leaving performance on the table.
- Stiffer Spring = More belt tension + higher RPM transition
- Softer Spring = Less belt tension + lower RPM transition
This spring is also available as part of our Stage 1 GY6 150 Performance Kit.
This product is intended for off-road use only. Not intended for use on public roads. Not legal for use in California.
