BIG BORE ENGINE KITS

More displacement. More torque. More performance.

Our Big Bore Kits are designed for riders looking to take their Harley-Davidson engine beyond stock limitations. Whether you're building a strong street machine or a high-performance touring motor, increasing displacement is one of the most effective ways to unlock real power gains.

We offer proven big bore solutions featuring premium components such as forged pistons, precision-machined cylinders, and high-quality gasket systems from trusted performance brands.

From mild torque upgrades to aggressive performance builds, these kits provide the foundation for serious horsepower.

3 products

Harley-Davidson Performance Kits

Big Bore Performance Kits for Harley-Davidson Motorcycles

Unlock unparalleled power and performance with our range of Big Bore Engine Performance Kits at Hoban Brothers Motorcycles. Perfectly engineered to enhance your Harley-Davidson motorcycle, our kits provide significant boosts in horsepower and torque, turning your ride into a high-performance machine.

Featured Kits

Street Glide Big Bore Kit: Elevate your Street Glide with our precision-engineered kits, designed for maximum performance and smooth cruising.

Road Glide Big Bore Kit: Boost your Road Glide’s power with our high-quality big bore kits, ensuring an exhilarating and responsive ride.

Ultra Big Bore Kit: Upgrade your Ultra for superior acceleration and torque, perfect for long-distance rides and high-speed performance.

Low Rider ST Big Bore Kit: Transform your Low Rider ST with our high-performance big bore kits, crafted for power and agility.

M8 Big Bore Kit: Maximize your M8 engine’s potential with our 128" Big Bore Kit, designed for upgrading from 114" / 117" engines. Experience a substantial increase in power and torque for a thrilling ride.

Why Choose Our Big Bore Kits?

Precision Engineering: Each kit is crafted for a perfect fit and optimal performance, ensuring your engine runs smoothly.

Superior Materials: Made from top-grade components for durability and reliability in all riding conditions.

Comprehensive Upgrade: Includes all necessary parts such as cylinders, pistons, and gaskets for a complete engine transformation.

Enhanced Performance: Enjoy faster acceleration, improved throttle response, and a more exhilarating riding experience.

Transform your Harley-Davidson with our high-performance Big Bore Engine Kits. Whether you’re upgrading your Street Glide, Road Glide, Ultra, Low Rider ST, or M8 engine, our kits are designed to deliver exceptional power and reliability. Shop now to dominate the road and enjoy the ultimate riding experience.