This M12x1.25 Flange Nut is a high-strength OEM replacement specifically designed for the GY6 engine platform. Featuring a smooth integrated flange base, this nut provides a wider surface area for more consistent clamping force, making it essential for securing high-vibration rotating components like the clutch bell and flywheel.
Primary Applications:
- Clutch Assembly: Secures the clutch bell/assembly to the transmission output shaft.
- Flywheel/Magneto: Holds the flywheel in place on the crankshaft (located between the flywheel and cooling fan).
Technical Specifications:
- Thread Size: M12 x 1.25 (Fine Thread)
- Socket Size: 17mm
- Outer Diameter (Base): 23.5mm
- Total Height: 8.85mm
- Material: Zinc-plated Steel
Engine Compatibility:
Designed for 4-stroke Chinese engines (GY6), including 125cc, 150cc, and 169cc variants. Fits engines with the following codes:
- 157QMJ / 1P57QMJ
- 152QMI / 1P52QMI
- 161QMK / 1P61QMK
- Other: BN157QMJ, JJ157QMJ, and generic QMI/QMJ clones.
157QMJ-based 125cc / 150cc / 169cc engines with the following engine codes:
| 157QMJ | 161QMK | 152QMI | 1P61QMK |
| YN1P57QMJ | 1P52FMI | 154FMI | JJ157QMJ |
| 1P57QMJ | BN157QMJ | BN161QMK-A | Other QMJ, QMK, and QMI models |
Don't see your engine listed? If the engine code includes "QM" or "FM", this product is compatible with your vehicle.
Tech Tip: These nuts are often "one-time use" in high-performance applications as the threads can stretch under the high torque required (approx 40-45 ft-lbs). Always use a drop of medium-strength thread locker to ensure the nut does not back off during operation.
About MotoTec USA: Since 1989, MotoTec USA has been the premier source for specialized scooter hardware. We stock genuine and high-quality aftermarket components for brands like Genuine, Wolf, TaoTao, and Vespa.
Original Parts For Scooters SKU 175-33
