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

S&S Cycle rear cylinder for 2017 Milwaukee-Eight models with a 4.250-inch bore, finished in wrinkle black. A bolt-on upgrade cylinder designed to increase displacement and power output when paired with compatible pistons and gasket sets.

Features

• 4.250 in bore diameter
• 2017 M8 engine compatibility
• Wrinkle black finish without highlight
• Complete rear cylinder casting

Specifications

• Brand: S&S Cycle
• Manufacturer Part #: 910-0674
• Bore Diameter: 4.250 in
• Position: Rear
• Weight: 11.83 lb
• Category: Engine Components / Piston Sets - Powersports

Fitment

Fits 2017 Harley-Davidson Milwaukee-Eight models. Part of S&S displacement kits — verify complete kit compatibility before ordering.

Frequently Asked Questions

Is this a complete piston kit or just the cylinder?

This is the cylinder only. You'll need pistons, wrist pins, rings, and gaskets to complete a full displacement kit.

What displacement increase will this give my 2017 M8?

Displacement gain depends on the piston compression ratio and stroke of your complete kit. Consult S&S documentation for your specific configuration.

Can I use this cylinder with other aftermarket pistons?

Check S&S compatibility specs. This cylinder is engineered for S&S piston kits — mixing brands may result in improper fit or damage.

What tools or machine work will I need?

Professional engine machine work and assembly are required. This is not a bolt-on mod — expect full top-end teardown and rebuild.