Automotive parts upgrade aimed at turning low-powered GY6 scooters into a higher-displacement setup with improved hill-climbing performance. Riders who need steadier acceleration while carrying luggage or a passenger will welcome a straightforward rebuild kit from TRKIMAL Cylinder Kits. Will the kit match your GY6 engine and mechanical skills?
⚡ At a Glance
- • Performance Gain: Increases displacement by moving to a 50mm bore, improving low-end torque for climbs
- • Best for: Owners of GY6 49cc/50cc (139QMB) scooters wanting a straightforward big-bore upgrade
- • Not ideal for: Users without mechanical experience or engines outside the GY6 139QMB family
50mm bore and matched piston components enable an upgrade from 50cc to 100cc. The package includes piston, rings, gaskets and hardware for a full rebuild.
More hill-climbing power – Thanks to 50mm cylinder bore
Enlarging the cylinder bore to 50mm increases swept volume, effectively raising engine capacity from a 50cc baseline toward the stated 100cc upgrade. Larger bore and matched piston dimensions produce higher torque at lower revs.
Steeper inclines feel less taxing and overtaking becomes more confident, especially when carrying a passenger or luggage.
Complete rebuild in one box – With piston, rings and full gasket set
The parts list includes cylinder, piston, piston ring, piston pin and clip, valve oil seal, multiple gaskets, tensioner gasket, exhaust gasket, intake and exhaust studs, plus an exhaust nut. All critical sealing and wear components are supplied together.
Sourcing individual parts is unnecessary, shortening workshop time and reducing the chance of mismatched components during the rebuild.
Easier fitment – With matched piston and pin dimensions
Piston outer diameter and cylinder bore both measure 50mm, while the piston pin outer diameter is 13mm, ensuring dimensional compatibility for the GY6 139QMB family. Included studs and fasteners align with common GY6 mounting points.
Measurements that match common GY6 specifications cut down on machining and adjustment, helping achieve correct clearances during assembly.
✨ The 4 Key Reasons for TRKIMAL Cylinder Kits
- Full hardware package — Reduces parts-sourcing time and workshop visits
- Matched piston dimensions — Ensures correct clearances and smoother assembly
- Includes valve oil seal — Helps prevent oil seepage around valves after rebuild
- Contains intake and exhaust studs — Prevents delays caused by missing fasteners
📋 Technical Details at a Glance
- Category: Automotive Parts and Accessories
- Product Type: Cylinder Kit
- Bore (Inner Diameter): 50mm
- Piston Outer Diameter: 50mm
- Piston Pin Outer Diameter: 13mm
❓ Frequently Asked Questions
Q: Will this kit convert a 50cc GY6 engine to 100cc?
A: Product descriptions state the cylinder bore increases to 50mm and the kit is intended as an upgrade from 50cc to 100cc for compatible GY6 engines.
Q: What parts are included in the kit?
A: Included items are cylinder, piston, piston ring, piston pin and clip, valve oil seal, gaskets, tensioner gasket, exhaust gasket, intake and exhaust studs, and an exhaust nut.
Q: Which engines are compatible with the kit?
A: Compatibility is specified for GY6 49CC/50CC engines including 139QMB variants; confirm mechanical fitment against your engine before purchase.
🏆 Our Verdict
The TRKIMAL Cylinder Kits suit mechanically confident owners of GY6 49/50cc scooters who want stronger low-end torque and better hill-climbing. A 50mm bore combined with a full piston and gasket set is the core selling point, supplying most parts needed for a rebuild. Although an upfront investment is required, the included hardware and performance gains offer durable value over time.
