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

S&S Cycle cylinder and piston kit for Milwaukee-Eight Harley-Davidson big twins (2017+), engineered to bore the engine to 4.25 inches and pair with S&S stroker cranks for 131 cubic inches of displacement. Forged pistons and tight tolerances deliver significant horsepower gains while retaining stock engine height and casings.

Features

• Forged piston design
• 4.25" cylinder bore
• Powder coat finish matches factory appearance
• 0.030" MLS head gaskets included
• Works with stock crankcases
• Retains original engine height
• Includes 131" displacement cam cover badge

Specifications

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

Fitment

Fits Harley-Davidson Milwaukee-Eight engines (2017 and newer big twins). Must be paired with S&S stroker flywheels (part #s 320-0605 or 320-0620) to achieve the full 131 cubic inch displacement.

Frequently Asked Questions

What displacement does this kit produce?

131 cubic inches when combined with S&S stroker flywheels (part #s 320-0605 or 320-0620). The cylinders alone bore the engine to 4.25 inches.

Will I need to replace my crankcase?

No — this kit works with stock crankcases, so you can use your existing bottom end.

Does this require engine removal for installation?

Yes, this is a major engine build requiring disassembly. Professional machine shop installation is recommended.

Will my engine serial number be retained?

Yes — original engine serial numbers are retained through the build.

What about carburetor tuning or fuel mapping?

With a 131-inch displacement increase, your fuel system and ignition will require recalibration. Consult S&S or a Harley tuner for mapping specifics.