39mm Cylinder Head with 64mm Valves for GY6 50cc 139QMB 4-Stroke Scooter ATV

Product Overview

Upgrade or repair your engine with this high-performance 39mm Cylinder Head, specifically designed for 4-stroke GY6 49cc/50cc engines. Featuring pre-installed 64mm valves, this head is engineered for optimal heat dissipation and long-term durability. It is a direct replacement part designed to restore compression and reliability to your scooter, moped, or ATV.

Product Compatibility

This cylinder head is compatible with the 139QMB / 139QMA engine platform, found in a wide variety of Chinese-manufactured scooters and ATVs.

Vehicle Type	Popular Compatible Brands/Models
Scooter / Moped	TaoTao (VIP, Pony), Peace Sports, Ice Bear, Wolf, Bintelli, Kymco Agility 50
ATV / Quads	Buyang, Coolsport, Kazuma, Sunl, Roketa
Engine Brands	Zongshen, Lifan, Loncin, Jianshe

Note: Specifically fits engines using 64mm length valves. Does not fit "Tall Head" versions (69mm valves).

Specifications

Feature	Measurement
Cylinder Bore	39mm
Valve Length	64mm (Standard)
Intake Valve Diameter	18.6mm
Exhaust Valve Diameter	16.0mm
Mounting Hole Distance	50mm (Center to Center)
Engine Cycle	4-Stroke

Key Features

• Precision Fit: Engineered specifically for 139QMB/139QMA engines with 50mm mounting spacing.
• Superior Cooling: Advanced heat dissipation fins prevent overheating during extended rides.
• Ready to Install: Comes with 64mm intake and exhaust valves pre-seated for convenient replacement.
• Enhanced Durability: Built from high-toughness, corrosion-resistant alloy to withstand high combustion pressures.
• Reliable Performance: Meets or exceeds OEM standards to ensure smooth idling and consistent power delivery.