S&S Cycle Cylinder & Piston Kits — Harley-Davidson Electra Glide, Electra Glide Classic, Electra Glide Ultra Classic (1955-2026)

S&S Cycle cylinder and piston kit for 2017+ Harley-Davidson Touring with Milwaukee-Eight engines, engineered to increase displacement and horsepower over factory M8 specification. Precision-machined pistons and cylinder bores deliver repeatable performance gains on stock or modified engines.

Features

• 4.250 in x 4.375 in bore and stroke
• Designed for 2017+ M8 Touring engines
• Precision-machined pistons and cylinders
• S&S Cycle engineering and quality control

Specifications

• Brand: S&S Cycle
• Manufacturer Part #: 920-0135
• Displacement / Size: 4.250 in x 4.375 in
• Weight: 3.22 lb
• Category: Engine Components / Piston Sets - Powersports

Fitment

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

Frequently Asked Questions

Will this fit my pre-2017 Touring with Twin Cam?

No — this kit is designed specifically for 2017+ Milwaukee-Eight engines. Twin Cam Touring models require a different S&S Cycle piston and cylinder kit.

What kind of horsepower increase can I expect?

Horsepower gain depends on engine tuning, fuel octane, and other modifications. Consult S&S Cycle's performance charts or contact a Harley tuner for your specific setup.

Do I need to rejet or retune the carb after installation?

Yes — a fuel and air recalibration is recommended to optimize performance with the increased displacement. Have a professional tuner calibrate your ECU.

Is installation a DIY job or does it require a shop?

This is an advanced engine buildup requiring motor removal, machine work, and precise assembly. Professional installation at a qualified Harley shop is strongly recommended.