MXT Cylinder Standard 50 ccm AC 39 mm bore 13 mm piston pin complete with piston and gasket set for GY6 4-stroke 139QMA / 139QMB / Chinese scooter / Baotian, Benzhou, Kymco, Peugeot

This cylinder from MXT is an aluminum replacement cylinder in original equipment manufacturer specification for air-cooled 50cc 4-stroke engines of the GY6 type (139QMB / 139QMA), as installed in import, hardware store, and Chinese scooters. It corresponds to the original series in bore size and dimensions and is therefore suitable for operation on public roads. Included in the scope of delivery are the cylinder, aluminum piston (CNC-machined), piston rings including oil scraper rings, 13 mm piston pin, piston clips, cylinder base gasket, cylinder head gasket, and carburetor flange gasket.

Product features:

• Aluminum cylinder 50 ccm in original equipment manufacturer specification - dimensionally identical to the original series, suitable for road use
• Cylinder bore 39 mm, piston pin 13 mm - corresponds to the standard dimension of the GY6 engine
• Direct replacement for the series cylinder without adjustments
• Aluminum piston (CNC-machined) with 2 oil grooves in the piston skirt for improved lubrication on the running surface and in emergency operation
• Piston pin bearing points with 2 oil holes and 1 groove each for better piston pin lubrication
• Piston with arrow marking on the piston crown to indicate the installation direction

The structurally improved lubrication at the piston skirt and piston pin bearing points is designed for continuous operation under the simple maintenance conditions under which GY6 engines of this class are typically operated.

Technical details:

• Product category: Cylinder with piston and gasket set
• Displacement: 50 ccm
• Engine type: GY6 4-stroke (139QMB / 139QMA, air-cooled)
• Version: Standard, original equipment manufacturer specification
• Cylinder material: Aluminum
• Piston material: Aluminum (CNC-machined)
• Cylinder bore: 39 mm
• Piston pin diameter: 13 mm
• Cylinder head flange mounting: 4-hole
• Manufacturer: MXT

Vehicle and model compatibility:

• The cylinder fits air-cooled 50cc 4-stroke engines of the GY6 type (139QMB / 139QMA) with 39 mm bore and 13 mm piston pin, installed in a variety of import and hardware store scooters from manufacturers Baotian, Benzhou, Flex Tech, Jonway, Kymco, SYM, REX, Nova Motors, Znen, Jmstar, Peugeot, Sachs, Kreidler, Motowell, Generic and others. Before purchase, the engine type, cylinder bore, and piston pin diameter of the vehicle must be checked, as vehicle-specific differences may occur in GY6 vehicles of this class.

Assembly and application notes:

• The cylinder is replaced directly with the series cylinder; mounting points and connection dimensions correspond to the original. The arrow on the piston crown must point toward the exhaust side during installation; all gaskets must be replaced during installation. After assembly, check the oil level and adhere to the tightening torques according to the manufacturer's specifications.

Note on checking before purchase:

• Before purchase, check the engine type (GY6 4-stroke, 139QMB / 139QMA), cylinder bore (39 mm), and piston pin diameter (13 mm) of the vehicle and compare the original part with the product images.

About the manufacturer MXT

MXT is the powerful private label of Heavy Tuned and stands for high-quality replacement and tuning parts for motorcycles, scooters, and geared mopeds.

As a reliable alternative to OEM parts, MXT offers a wide range of cylinder kits, carburetors, and crankshafts up to variomatic components, fairing parts, and batteries. The products impress with solid workmanship, precise fit quality, and a strong price-performance ratio.

Ideal for riders looking for durable replacement parts and tuning parts for many vehicle models.