50mm GY6 50cc (139QMB) Performance Cylinder Kit

50mm Performance Cylinder Kit for GY6 50cc Engines

This 50mm performance cylinder kit is designed for 50cc QMB139 4-stroke engines, providing a significant boost in power with the upgrade to an 80cc capacity. It includes all necessary components such as the cylinder, piston, piston rings, wrist pin, circlips, head gasket, and base gasket. This kit is an important choice among GY6 50cc scooter parts for those looking to improve their engine's performance. Proper installation is important to prevent engine damage, especially when used with stock cylinder heads.

Installation Considerations

When installing this performance cylinder kit, be prepared to adjust your engine casing for a proper fit of the larger cylinder. It is advisable to pair this kit with the QMB139 performance cylinder head for improved performance, as some stock heads may not be compatible. Using a stock head without modifications can lead to serious engine issues.

Components Overview

This kit features a cylinder bore of 50mm, with an outer diameter of 54.9mm for the cylinder sleeve. The wrist pin diameter is 13mm, and the total piston height is 34.8mm, with a compression height of 18.3mm from the center of the wrist pin hole to the top edge of the piston. These specifications are important for ensuring the performance gain and fitment of the components.

Specifications

• Cylinder Bore: 50mm
• Cylinder Sleeve Outer Diameter: 54.9mm
• Wrist Pin Diameter: 13mm
• Total Piston Height: 34.8mm
• Compression Height: 18.3mm

Fitment

This performance cylinder kit fits the following vehicles and engines:

• Baja SC50-P
• Jalon X8 Retro 50cc
• Lifan
• Panterra Fusion 50cc
• Qingqi QM50QT-4G
• Qingqi QM50QT-6V
• SUNL
• Schwinn
• Strada

Not sure it fits? Contact us with your scooter's make, model and year and we'll confirm the fit before you order.

Shop more: GY6 50cc Scooter Parts (139QMB) · GY6 Scooter Parts · Scooter Big Bore & Cylinder Kits · Scooter Parts