S&S Cycle 910-0683A M8 Big Bore Cylinder Set 4.250" Bore Non-Highlighted Wrinkle Black

The S&S Cycle M8 Big Bore Cylinder Set delivers a massive increase in capacity from 107" to 124" (4.375" stroke), or from 114"/117" CVO (4.5" stroke) to 128" with bolt-on installation ease, requiring no case boring or machine work. These stock length cylinders feature a 4.250" bore and are finished in wrinkle black with non-highlighted cooling fins for a stealthy, aggressive appearance.

Key Features:

• Stock length with 4.250" bore for maximum displacement
• Black wrinkle finish with non-highlighted fins
• Bolt-on kit requiring no machining
• Constructed from cast iron for exceptional durability
• Sold as a pair for complete engine rebuild
• Compatible with 2017-2023 Harley-Davidson M8 Touring and 2018-2023 M8 Softail models

Kit includes cylinders, MLS (Multi Layer Steel) head gaskets, cylinder base gaskets, cylinder dowels, exhaust gaskets, expansion plugs, and expansion plug tool. This big bore cylinder set allows you to build impressive displacement for significant horsepower and torque gains while maintaining reliable street performance. Features forged pistons with an 11:1 compression ratio for optimal power delivery.

Note: S&S recommends using their M8 Head Bolts (part number 900-1006) for all big bore applications. Not recommended for Tri-Glide or other three-wheel models due to the high-stress lugging nature of these vehicles.