39mm GY6 50cc (139QMB) Piston

39mm Piston for 50cc QMB139 Engines

Built for 50cc 4-stroke QMB139 engines, this 39mm piston is a core part of the engine. It helps keep a firm seal inside the combustion chamber. Swapping out a worn piston and its rings can cure problems such as smoke, heavy oil use, and weak compression. If you're looking at other GY6 50cc scooter parts, this one is worth considering for keeping your engine running well.

Signs It Needs Replacing

Think about replacing this piston if the engine starts to smoke or loses power, since these can point to worn rings. Keeping this component in good condition supports engine performance and helps your scooter last longer.

Specifications

• Outer Diameter: 39mm
• Overall Height: 33mm
• Piston Pin: 13mm
• Compression Height: 17.25mm
• Circlips: Included
• Fits: 50cc 4-stroke QMB139 engines (39mm bore), GY6 type

Compatibility

Compatible with:

• 50cc 4-stroke QMB139 engines

How to choose: Confirm the 39mm bore and 13mm piston pin match your cylinder, and only fit it in a QMB139 engine.

Browse further: GY6 50cc Scooter Parts (139QMB) · GY6 Scooter Parts · Scooter Pistons & Piston Rings · Scooter Parts