S&S Cycle Cylinder & Piston Kits — Harley-Davidson Street Glide, Softail Fat Boy 114, Road King Special (2017-2026)

S&S Cycle piston set for 2017+ Harley-Davidson Milwaukee-Eight (M8) engines, machined to 4.250 in x 4.375 in with .010 in oversize spec. Direct replacement for stock or mildly modified M8 motors requiring fresh rings and pistons.

Features

• 4.250 in x 4.375 in piston dimensions
• .010 in oversize specification
• Engineered for 2017+ Milwaukee-Eight (M8) engines
• Direct replacement pistons for stock builds

Specifications

• Brand: S&S Cycle
• Manufacturer Part #: 920-0141
• Piston Oversize: .010 in
• Weight: 3.22 lb
• Category: Engine Components / Piston Sets - Powersports

Fitment

Fits 2017 and newer Harley-Davidson Milwaukee-Eight (M8) engines.

Frequently Asked Questions

Will these pistons fit my Twin Cam engine?

No — this is specific to 2017+ Milwaukee-Eight (M8) engines. Twin Cam pistons are a different size and design.

Do I need new rings and gaskets when installing these pistons?

Yes — S&S recommends new piston rings, gaskets, and oil seals to ensure a proper seal and longevity.

Are these pistons forged or cast?

S&S manufactures high-quality performance pistons; consult the product datasheet or S&S for material specification details.

Can I use these in a stock 114cc M8 engine?

Yes — these are direct replacement pistons suitable for stock or mildly modified Milwaukee-Eight engines.