58.5mm (155cc) BIG BORE KIT FOR SCOOTER ATV KART WITH 150cc GY6 MOTORS

58.5mm 155cc Big Bore Kit for GY6 150cc Scooters, ATVs, and Karts

Transform your stock 150cc GY6 engine into a powerful 155cc powerhouse with this drop-in big bore kit, designed for maximum performance without requiring cylinder boring.

• 58.5mm Bore Diameter: Achieves 155cc displacement for a significant power increase over stock 150cc engines.
• No Boring Required: Installs directly onto stock GY6 blocks with 54mm spacing (A-Block) for a straightforward upgrade.
• Complete Performance Set: Includes a performance camshaft, rocker arm set, and valve cover with gasket for a comprehensive engine enhancement.
• Optimized Cylinder Design: Features a 60.4mm outer diameter and 68.60mm height, specifically engineered for compatibility and efficiency.
• Premium Piston & Rings: Comes with a KBF piston and rings set designed for durability and optimal compression.

This 58.5mm big bore kit offers a substantial upgrade compared to standard 150cc GY6 engines, unlocking more horsepower and torque for a thrilling ride. Unlike many kits that necessitate costly and time-consuming cylinder boring, this design is engineered for a "no boring required" installation on compatible GY6 A-Block motors, making it an accessible performance solution.

Key Technical Advantages: Technology and Performance

This kit leverages precision engineering to deliver enhanced engine performance and reliability. By increasing displacement to 155cc and incorporating performance-oriented components like a high-lift camshaft and upgraded rocker arms, it boosts horsepower and torque output. The included cylinder features a slightly smaller outer diameter (60.4mm vs. typical 65mm) and is designed for 54mm spacing A-block GY6 engines, ensuring a direct fit and optimal heat dissipation for sustained performance.