This big bore cylinder and piston kit contains S&S 4-1/8" bore cylinders and forged pistons, rings, wrist pins, head and base gaskets. The cylinders are machined with the stock bolt pattern and are intended for use in stock crankcases of 2007-'17 big twin except 20017 touring engines. The stock 4-3/8" stroke and 4-1/8" bore result in a 117' displacement. Cylinder finish is a durable wrinkle black powder coat. For best performance, appropriate camshafts, performance air cleaner, performance exhaust and fuel system tuning are required.Although not mandatory, we recommend adding an oil cooler to bikes ridden in warmer climates.

• Crankcases must be bored to accept the larger 4-1/8" bore cylinders
• Not recommended for Tri-Glide or other three wheel models including conversion due to lugging nature of these bikes
• When using Harley Twin Cooled heads, part number 900-0609 will have to be used