M12x1.25 Flange Nut - GY6 125/150cc Clutch & Flywheel

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:

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.

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Original Parts For Scooters SKU 175-33