GY6 100CC 50MM QMB139 Big Bore Engine Kit with 64mm Non-Emission Head

Upgrade your scooter or ATV with this comprehensive GY6 100cc 50mm Big Bore engine kit, designed for enhanced performance and power. This kit includes a high-performance cylinder head featuring 64mm valves and a non-emission (non-EGR) design, ensuring optimal airflow and combustion efficiency for your QMB139 engine.

• 50mm Bore Cylinder: Delivers a true 100cc displacement for significantly increased power output.
• 64mm Non-Emission Cylinder Head: Features larger intake (17mm) and exhaust (18mm) ports for superior gas flow.
• Performance Variator Kit: Includes an 87mm outer diameter variator with 8.5g roller weights for improved acceleration.
• Carburetor & Intake: Compatible with setups requiring a 19mm carburetor intake and a 40mm air filter mount.
• Complete Component Integration: Comes with essential parts like a 33-tooth oil pump gear and a 3/16" in-line fuel filter for a seamless installation.

Compared to stock 50cc engines or older QMB139 models, this 50mm big bore kit offers a substantial leap in performance. By increasing the bore size to 50mm, it significantly boosts displacement and torque, providing a more robust and responsive ride. The inclusion of a performance-tuned cylinder head with larger valves and a non-emission design further optimizes the engine's breathing capabilities, setting it apart from standard configurations and yielding greater horsepower.

Key Technical Advantages: Technology and Performance

This kit leverages advanced engineering for maximum power and reliability. The 50mm bore cylinder, paired with the precisely designed 64mm non-emission cylinder head, maximizes combustion volume and airflow. Performance-oriented components like the variator with specific roller weights and the optimized intake manifold dimensions ensure that the engine's power is delivered efficiently across the RPM range. The non-emission design removes restrictions, allowing for a purer, higher-output performance profile suitable for enthusiasts seeking an edge.