47mm Performance Big Bore Cylinder Kit (80cc Upgrade) for GY6 50cc 139QMB 4-Stroke Scooter ATV

Product Overview

Unlock hidden power in your GY6 engine with the GOOFIT 47mm Big Bore Cylinder Kit. Designed to upgrade standard 49cc/50cc units to 80cc, this kit is the perfect balance of performance and reliability. Crafted from high-strength aluminum alloy with a wear-resistant coating, it provides an immediate boost in torque and acceleration without the need for complex engine modifications.

Product Compatibility

A universal top-end upgrade for 4-stroke GY6 horizontal engines.

Engine Platform	Upgrade Potential	Fitment Type
GY6 49cc / 50cc	Upgrades to 80cc	Standard 139QMB / 139QMA
GY6 60cc / 80cc	Direct Replacement	Maintenance & Repair
Compatible Vehicles	ATVs, Scooters, Mopeds, Karts	TaoTao, Peace Sports, Wolf, Ice Bear

Specifications

Attribute	Details
Cylinder Inner Diameter	47mm / 1.85"
Piston Pin Outer Diameter	13mm / 0.51"
Engine Type	4-Stroke GY6 (139QMB)
Material	High-Strength Aluminum Alloy
Coating	Premium Wear-Resistant Hardened Layer

Key Features

• Instant Performance Upgrade: Efficiently increases your displacement to 80cc, providing the extra power needed for hills, passengers, and higher cruising speeds.
• Thermal-Stable Construction: Made of premium aluminum alloy that dissipates heat faster than stock cast iron, ensuring stable performance during long-distance rides.
• Wear-Resistant Hardened Bore: The inner cylinder wall features a specialized coating that reduces friction and extends the life of the piston rings and cylinder.
• Quick & Simple Installation: Engineered as a "Bolt-On" solution, this kit requires no machining or complex modifications to your original crankcase.
• Comprehensive Accessory Pack: Includes everything for a professional seal: cylinders, pistons, rings, valve seals, and a full set of gaskets, bolts, and exhaust nuts.