Big Bore Cylinder Kit For GY6 139QMB 139QMA Scooters Rebuild Kit Includes 50mm Piston Piston Ring Piston Pin Piston Pin Clip Gaskets Seals Studs Exhaust Gasket For 100cc Moped ATV Go Kart

50mm GY6 Cylinder Kit single rebuild for 100cc Scooters
✔️ 50mm bore cylinder kit, single rebuild with piston, rings

This rebuild kit is designed for the GY6 139QMB 4-stroke engine and is a popular upgrade for Chinese-made scooters, ATVs, and go-karts, offering a complete set for a reliable rebuild.

✅ Cylinder bore: 50 mm (1.97 in)
✅ Piston pin diameter: 13 mm (0.51 in)
✅ Includes: cylinder, piston, piston ring, piston pin, piston pin clip, valve oil seal, gaskets, tensioner gasket, exhaust gasket, intake & exhaust studs, exhaust nut
✅ Fits GY6 139QMB 4-stroke engines used in 100cc scooters, ATVs, Go-Karts

💡 What is a pillow block bearing used for in mechanical systems?

In short, it provides a stable housing for shafts and makes mounting and lubrication handy.

- Supports rotating shafts in conveyors, motors, and machinery
- Helps align and protect bearings to reduce wear and downtime
- Works with standard bearing configurations for easy upgrades
- Handy for longer life and easier maintenance in small- to mid-size setups