62.5mm Big Bore Cylinder & Head Rebuild Kit for 4-Stroke GY6 150cc 180cc 200cc Upgrade 157QMJ 152QMI

Product Overview

Unleash the maximum potential of your GY6 platform with the GOOFIT 62.5mm Extreme Big Bore Kit. This comprehensive power package is engineered to upgrade standard 150cc (157QMJ) engines into high-displacement 180cc/200cc beasts. Combining a high-grade aluminum alloy cylinder with a precision-machined head, this kit delivers explosive torque and superior heat management, ensuring your ATV, UTV, or racing scooter dominates any terrain.

Product Compatibility

This 62.5mm Extreme Big Bore Kit is engineered as a high-performance upgrade for the standard GY6 150cc platform.

Category	Compatibility Details
Compatible Engine Codes	GY6 150cc: 157QMJ, 157QMI, 152QMI, 152QMJ
Engine Platform	4-Stroke Air-Cooled Horizontal Engines
Performance Upgrade	Boosts standard 150cc to 180cc / 200cc / 250cc Class
Vehicle Types	Performance ATVs, UTVs, Racing Scooters, Go-Karts
Supported Brands	TaoTao, Coolster, Ice Bear, Roketa, Bacci, Wolf, & other GY6 Clones
Fitment Note	Designed for 15mm Piston Pin configurations

Specifications

Attribute	Technical Details & Measurements
Engine Type	4-Stroke GY6 Horizontal
Cylinder/Piston Bore	62.5mm / 2.46" (Extreme Big Bore)
Piston Pin Diameter	15mm / 0.59"
Distributor Diameter	28mm / 1.1"
Material	Premium Aluminum Alloy & High-Temp Steel Liner
Cooling System	Optimized Air-Cooled Fins
Package Includes	Cylinder Block, Cylinder Head, Piston, Rings, Pin, Clips, Gaskets

Key Features

• Extreme Displacement Boost: The massive 62.5mm bore significantly increases engine capacity, providing a dramatic surge in horsepower and low-end torque for competitive off-road performance.
• High-Performance Head Design: Features an optimized combustion chamber that ensures faster flame propagation and higher compression, resulting in peak fuel efficiency and power output.
• Hybrid Material Construction: Combines lightweight aluminum for rapid heat dissipation with a high-temperature resistant steel liner for maximum wear resistance under racing conditions.
• All-Terrain Reliability: Meticulously engineered to maintain stable operation during high-load, extreme-temperature use, extending the overall lifespan of your modified engine.
• Complete Top-End Solution: A fully matched kit including the cylinder head and gaskets, designed for a seamless fit and eliminating the guesswork of mixing and matching performance parts.