✓ VERIFIED
Sep 26, 2019
Really nice kit great directions for install and ring gap. Follow the directions and you can't go wrong..
Image coming soon
S&S CYCLE
SKU: T14-852159
S&S Cycle Cylinder & Piston Kits — Harley-Davidson Street Glide, Softail Fat Boy 114, Road King Special (2017-2026)
$1,643.95
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S&S Cycle big-bore cylinder and piston kit for 2017+ Harley M8 models, offering a bolt-on 114 to 128 cubic inch displacement upgrade without machining. Includes forged pistons, cylinders in wrinkle black, gaskets, and all hardware needed for installation.
Features
- 114 to 128 cubic inch big-bore displacement
- Forged pistons with 11:1 compression ratio
- Bolt-on installation — no machining required
- Wrinkle black finish without highlighted fins
- All gaskets and mounting hardware included
Specifications
- Brand: S&S Cycle
- Manufacturer Part #: 910-0685A
- Displacement Range: 114 to 128 cubic inches
- Compression Ratio: 11:1
- Piston Type: Forged
- Finish: Wrinkle black
- Weight: 29.56 lbs
- Category: Engine Components / Piston Sets - Powersports
Fitment
Fits 2017 and newer Harley-Davidson M8 models. For closed-course competition use only.
Frequently Asked Questions
Will this kit fit my 2017+ M8 Harley?
Yes — this kit is designed specifically for 2017 and newer M8 models with 4.250 in bore and 4.500 in stroke.
Do I need to have my cylinders machined?
No — this is a bolt-on kit that requires no machining or modifications to your engine block.
What's included in the box?
Cylinders, forged pistons, gaskets, and all hardware needed to complete the installation.
Is this street legal?
This kit is for closed-course competition use only and is not street legal.
What compression ratio does this kit have?
The forged pistons deliver an 11:1 compression ratio for high-performance power.
| BRAND | S&S Cycle |
| TYPE | Piston Sets - Powersports |
| SKU | T14-852159 |
| WEIGHT | 29.56 lb |
Please contact us to confirm fitment for your specific motorcycle, or check the product title for compatibility notes.
CUSTOMER REVIEWS
4.88
8 RATINGS
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✓ VERIFIED
Apr 26, 2022
Excellent service and pricing im very satisfied
✓ VERIFIED
Sep 26, 2019
Better than OEM.. can't go wrong.
✓ VERIFIED
Mar 30, 2026
Very happy with this kit
Simple, easy kit.
✓ VERIFIED
Mar 29, 2026
SMS makes great aftermarket upgrades
✓ VERIFIED
Oct 24, 2025
👍👍 For fast delivery
Parts came just like as expected. They look great! Can't wait to install these bad boys along with a few other parts.