GY6 50cc (139QMB) Scooter 39mm 50cc Cylinder Kit
ITEM# TT-23980
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Description
39mm Cylinder Kit for GY6 50cc Scooters
This 39mm cylinder kit is designed for a complete top-end rebuild on 50cc scooters that use the 139QMB engine. It suits scooters showing oil consumption, lost compression, or general wear, and gives you the parts needed for a fresh rebuild in one set. It is also one of the simpler GY6 50cc scooter parts to fit yourself at home.
What Comes in the Kit
The package contains a cylinder, piston, piston rings, wrist pin, fasteners, dowel pins, and every gasket needed. Its stock 39mm bore matches the original components, so it drops in as a direct replacement with no modification. Gaskets for the head, base, and intake are all supplied, so the set is complete.
Installation and Care
Clean all gasket surfaces thoroughly before assembly. The new gaskets are included to help you achieve a proper seal. After fitting, follow a break-in period over the first miles to keep the engine performing as it should.
Specifications
- Bore: 39mm
- Displacement: 50cc
- Overall Cylinder Height: 70mm
- Cylinder Sleeve Outer Diameter: 44.7mm
- Engine Type: 4-stroke, air-cooled
- Includes: Cylinder, piston, piston rings, wrist pin, 2 circlips, 2 dowel pins, head gasket, base gasket, intake gasket
- OEM Part Number: 151-257
- Fits: 139QMB and 139QMA GY6 50cc 4-stroke engines (39mm bore, 44.7mm sleeve)
Compatibility
Compatible with:
- 139QMB GY6 50cc engines (codes 139QMB, 1P39QMB, YN139QMB, JJ1P39QMB, BD1P39QMB, BN139QMB)
- 139QMA GY6 50cc engines (codes 139QMA, 1P39QMA-2)
- Tao Tao scooters with 139QMB or 139QMA engines
- ZNEN scooters with 139QMB or 139QMA engines
- Peace Sports scooters with 139QMB or 139QMA engines
- Icebear scooters with 139QMB or 139QMA engines
- Jonway scooters with 139QMB or 139QMA engines
- Wolf scooters with 139QMB or 139QMA engines
- Baccio scooters with 139QMB or 139QMA engines
- Bintelli scooters with 139QMB or 139QMA engines
- BMS scooters with 139QMB or 139QMA engines
- Schwinn scooters with 139QMB or 139QMA engines
- SunL scooters with 139QMB or 139QMA engines
How to choose: Find the engine code stamped on your scooter and match it to 139QMB or 139QMA. Then confirm that your original cylinder measures 39mm bore and a 44.7mm sleeve diameter.
Browse related parts: GY6 50cc Scooter Parts (139QMB) · GY6 Scooter Parts · Scooter Big Bore & Cylinder Kits · Scooter Parts
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