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United Express Distribution  |  SKU: HEAD-1064-U1
17% off

100cc Head Assembly (64mm) for Scooter Big Bore Kit

Sale price $33.00 Regular price $39.97


Pickup available at 2875 N Berkeley Lake Rd NW #4

Usually ready in 1 hour

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Description

Upgrade your scooter’s performance with the 100cc Big Bore Kit featuring 64mm valves, engineered specifically for GY6 139QMB engines. This high-performance cylinder head assembly is designed to deliver a significant increase in power, torque, and overall engine efficiency. With precision-machined 64mm valves and a larger displacement, this kit ensures enhanced airflow and optimized combustion, resulting in quicker acceleration and a higher top-end speed. Whether you're commuting through city streets or cruising on open roads, this upgrade transforms your ride into a powerful, responsive machine.

Built for durability and reliability, the 100cc Big Bore Kit is crafted from premium materials and manufactured to meet stringent quality standards. Its robust design withstands high-performance demands while ensuring a long service life. The bolt-on design allows for easy installation, making it perfect for DIY enthusiasts or professional mechanics looking for a dependable performance boost. Compatible with a wide range of Chinese-made scooters and mopeds running QMB139/QMI139 4-stroke engines, this upgrade is your ticket to a more thrilling and dynamic riding experience.
  • Perfect Fit: Outfitted with oversized 64mm valves, 18mm intake and 16mm exhaust, this cylinder head allows superior air/fuel intake and exhaust flow. The enhanced combustion efficiency translates to smoother throttle response, more complete fuel burn, and improved fuel economy, even while delivering enhanced power output.
  • Wide Compatibility: Compatible with a wide variety of Chinese-manufactured 50cc to 100cc mopeds and scooters, including brands like TaoTao, Jonway, Peace Sports, and more. Whether you're upgrading an old ride or building a custom scooter, this performance cylinder head ensures a reliable fit and optimized performance across the board.
  • Massive Power: Experience an instant surge in engine performance with this 100cc Big Bore Kit. Designed to significantly increase displacement from standard 50cc/80cc engines, this kit provides a dramatic improvement in torque and horsepower, allowing faster acceleration and a noticeable boost in top-end speed for GY6 139QMB scooters.
  • Durable Construction: Manufactured with premium-grade materials, this cylinder head and valve assembly ensures long-lasting durability under high-heat and high-RPM conditions. The robust build quality is ideal for performance riders, daily commuters, and anyone looking for a reliable upgrade that can withstand extended use without compromise.
  • Easy Installation: This big bore kit is designed as a direct bolt-on replacement for QMB139/QMI139 4-stroke engines with compatible intake (44.75mm) and exhaust (49.75mm) bolt hole spacing. Its user-friendly design makes installation straightforward for DIY users and professionals alike, no complex modifications required.
Specs:
  • 64mm Valves
  • Intake Bolt Hole Spacing: 44.75mm
  • Exhaust Bolt Hole Spacing: 49.75mm
  • Intake Valve Diameter: 18mm
  • Exhaust Valve Diameter: 16mm
Known to Fit: 
  • Upgraded 100cc Cylinder Head & Valve Assembly QMB139 / QMI139 4-Stroke Engines.
  • Exact replacement part for many Chinese-manufactured brands and models of Chinese Mopeds and Scooters. 

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