GY6 Piston Set

GY6 Piston Kit for 125cc and 150cc Motors

This GY6 piston kit, which includes the piston and rings, is built for 125cc and 150cc GY6 4-stroke motors. It comes in 58.5mm, 61mm, and 63mm bore sizes and is a practical choice for anyone moving up to a Big Bore cylinder kit. It is one of several GY6 scooter parts that can help boost engine output. Keep in mind that the 61mm piston will not work with 161QMK engines.

Piston Details

The kit uses a 15mm piston pin and has a 20mm compression height. Together these dimensions help the piston seat correctly and compress the fuel mixture as intended. When picking a size, go with the one that suits your engine setup so the upgrade goes smoothly.

When to Replace and Use

The piston plays a major role in how efficiently your GY6 engine runs, so it is worth paying attention to its condition during a rebuild. Common warning signs include strange noises from the engine, a drop in power, and oil use that seems higher than normal. Routine inspections can help you keep the engine running well for longer.

Specifications

• Size: 58.5mm, 61mm, 63mm
• Piston Pin Diameter: 15mm
• Compression Height: 20mm
• Fits: GY6 4-stroke 125cc and 150cc Big Bore cylinder kits, 58.5mm, 61mm and 63mm sizes

Compatibility

Fits:

• GY6 QMI/QMJ 152/157 engines (150cc, 4-stroke)
• GY6 125cc and 150cc 4-stroke engines with Big Bore cylinder kits (various unlisted makes/models)

How to choose: Select the piston size that matches your Big Bore cylinder bore: 58.5mm, 61mm or 63mm. The 61mm piston is not designed for 161QMK engines.

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