S&S Cycle 4.250 Inch Big Bore Cylinder Set for 2017-Up Harley-Davidson M8

S&S Cycle 4.250 Inch Big Bore Cylinder Set for 2017-Up Harley-Davidson M8

The Milwaukee-Eight platform responds well to displacement, and the S&S 4.250 inch big bore cylinder set is the foundation of a serious M8 performance build. Cast in a distinctive black granite finish with highlighted cooling fins, these cylinders are engineered to the dimensional tolerances that M8 big bore work demands – and S&S recommends pairing them with their 900-1006 M8 head bolts for a complete top-end upgrade.

Key Features

• 4.250 inch bore cylinders for significant displacement increase on M8 engines
• Black granite finish with highlighted cooling fins for premium appearance
• Engineered specifically for Milwaukee-Eight Touring and Softail platforms
• Compatible with S&S M8 big bore pistons and head gasket kits
• S&S recommends pairing with 900-1006 M8 head bolt kit for all big bore applications

Technical Specifications

• Bore: 4.250 inches
• Finish: Black granite with highlighted fins
• Platform: Harley-Davidson Milwaukee-Eight (M8)
• Fitment: 2017-2023 Touring M8 / 2018-2023 Softail M8
• Recommended Hardware: S&S 900-1006 M8 head bolt kit

Fitment Notes

• Fits 2017-2023 Harley-Davidson Touring models with Milwaukee-Eight engine
• Fits 2018-2023 Harley-Davidson Softail models with Milwaukee-Eight engine
• Pistons, rings, gaskets, and head bolts sold separately – this is a cylinder set only
• S&S strongly recommends upgrading to S&S 900-1006 M8 head bolts for all big bore installations
• Review the Fitment tab for the complete year and model breakdown