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

S&S Cycle 131-cubic-inch cylinder and piston kit for Milwaukee-Eight Harley-Davidson big twins (2017 and newer), engineered to deliver significant displacement and power gains over stock. Forged pistons pair with 4.25" cylinders and require S&S stroker flywheels and crank to achieve full 131" displacement.

Features

• Forged piston design
• 4.25" cylinders
• Powder coat finish matches factory appearance
• 0.030" MLS head gaskets included
• Works with stock crankcases
• Retains stock engine height
• Includes 131" displacement badge
• Original engine serial numbers retained

Specifications

• Brand: S&S Cycle
• Manufacturer Part #: 910-0762A
• Category: Engine Components / Piston Sets - Powersports
• Weight: 27.06 lb

Fitment

Fits Milwaukee-Eight Harley-Davidson big twins, 2017 model year and newer. Requires S&S stroker flywheels (part numbers ssc320-0605 or ssc320-0620) to achieve the full 131-cubic-inch displacement.

Frequently Asked Questions

What displacement do these cylinders and pistons deliver?

131 cubic inches when paired with S&S stroker flywheels and crank. Stock stroke delivers less displacement.

Do I need to buy S&S stroker flywheels separately?

Yes — to achieve 131" displacement, you must use S&S stroker flywheels (ssc320-0605 or ssc320-0620). The cylinders and pistons alone will not reach 131".

Will this fit my pre-2017 Harley?

No — this kit is designed for Milwaukee-Eight engines in 2017 and newer models only.

Do these raise my engine height?

No — the kit retains stock engine height despite the larger displacement.

Will I lose my original engine serial number?

No — original engine serial numbers are retained during the big bore installation.