Big Bore Cylinder Kit — 4.250" bore, 4.500" stroke, 128 cu in, Black

S&S CYCLE Big Bore Cylinder Kit — 4.250" bore, 4.500" stroke, 128 cu in, Black – 18-26 Softail, 19-26 Touring, 22-23 CVO, 20-25 Trike

S&S CYCLE
0931-0835
910-0685
Drop-in Big Bore kit includes cylinders, pistons, rings and gaskets. Easy installation; requires a skilled technician to verify clearances and specs.
Hurry! only 9 items left in stock.
€1,190.34
€1,495.82
Save €305.48
local_shipping In stock, ships in 2-3 days
Quantity

  Delivery policy

In stock items will be shipped within 1-3 days.

  Return policy

You can return the products within 14 days for a full refund, check our returns policy.

Upgrade your engine with the Big Bore Cylinder Kit — a drop-in solution for noticeable performance gains. 🔧

  • Big Bore kit yields excellent results with stock cylinder heads.
  • Easy installation: no need to bore or split existing cases; just swap the cylinders unless otherwise noted.
  • Cylinders are constructed from premium aluminum castings with cast-in iron liners.
  • Kit includes cylinders, pistons, rings and gaskets (head, base and exhaust).
  • Made in the USA 🇺🇸.
  • Project requires a skilled technician. It is the responsibility of the person assembling the parts to check all clearances and assembly specifications.

Designed for riders and builders who demand reliable power and durability.

: 0931-0835
In Stock

Data sheet

Color/Finish
Black
Base Color
Black
Brand
S&S CYCLE
Bore Size
4,250"
Compression Ratio
11.0:1

Shipping Policy

Shipping Areas:

We ship to:

  • Spain (Peninsula and Balearic Islands)
  • European Union countries

We do not ship to the Canary Islands, Ceuta, or Melilla.

Shipping Times:

  • Spain (Peninsula): 2–4 business days
  • Balearic Islands: 3–5 business days
  • EU countries: 3–7 business days depending on destination

Shipping Costs:

Shipping costs are calculated automatically at checkout based on destination and weight.

Free shipping may be offered for qualifying orders, as specified on our website.

Order Processing:

Orders are processed within 1–2 business days after payment confirmation. Orders placed on weekends or public holidays are processed the next business day.

Delivery Issues:

If your order is delayed or arrives damaged, you must notify us within 14 calendar days. We will investigate the issue and offer a resolution in accordance with applicable consumer protection laws.

Return & Withdrawal Policy

Right of Withdrawal:

In accordance with Royal Legislative Decree 1/2007 (Ley de Defensa de los Consumidores y Usuarios), you have the right to withdraw from your purchase within 14 calendar days from the date of receipt, without giving any reason.

To exercise this right, contact us via email or through our website, providing your order number and contact details.

Return Conditions:

  • Products must be unused, in original condition and packaging.
  • Return shipping costs are the responsibility of the customer, unless the product is defective or sent in error.
  • Refunds will be issued within 14 days of receiving the returned goods.

Items Excluded from Return:

  • Custom or personalized products
  • Sealed items that were unsealed after delivery and are unsuitable for return due to hygiene (e.g. cosmetics, personal care)
  • Digital content delivered electronically once download or streaming has begun

If you want to return an item, please contact us first to give you detailed instructions.

This product fits the following vehicles. Use the filters below to narrow down the list if needed.

Manufacturer Model Family Year Notes
Harley Davidson Softail Fat Boy Anniversary (ANX) 114 Softail 2018
Harley Davidson Softail Fat Boy 114 Softail 2019
Harley Davidson Softail Fat Boy 114 Softail 2020
Harley Davidson Softail Fat Boy 114 Softail 2021
Harley Davidson Softail Fat Boy 114 Softail 2022
Harley Davidson Softail Fat Boy 114 Softail 2023
Harley Davidson Softail Fat Boy 114 Softail 2024
Harley Davidson Softail Fat Boy 117 Softail 2025
Harley Davidson Softail Fat Boy 117 Softail 2026
Harley Davidson Electra Glide Revival 114 Touring 2021
Harley Davidson Softail Heritage Classic 114 Softail 2018
Harley Davidson Softail Heritage Classic 114 Softail 2019
Harley Davidson Softail Heritage Classic 114 Softail 2020
Harley Davidson Softail Heritage Classic 114 Softail 2021
Harley Davidson Softail Heritage Classic 114 Softail 2022
Harley Davidson Softail Heritage Classic 114 Softail 2023
Harley Davidson Softail Heritage Classic 114 Softail 2024
Harley Davidson Softail Heritage Classic 117 Softail 2025
Harley Davidson Softail Heritage Classic 117 Softail 2026
Harley Davidson Road King Special 114 Touring 2019
Harley Davidson Road King Special 114 Touring 2020
Harley Davidson Road King Special 114 Touring 2021
Harley Davidson Road King Special 114 Touring 2022
Harley Davidson Road King Special 114 Touring 2023
Harley Davidson Road King Special 114 Touring 2024
Harley Davidson Road King Special 114 Touring 2025
Harley Davidson Street Glide 117 Touring 2024
Harley Davidson Street Glide 117 Touring 2025
Harley Davidson Street Glide 117 Touring 2026
Harley Davidson Street Glide Special 114 Touring 2019
Harley Davidson Street Glide Special 114 Touring 2020
Harley Davidson Street Glide Special 114 Touring 2021
Harley Davidson Street Glide Special 114 Touring 2022
Harley Davidson Street Glide Special Anniversary 114 Touring 2023
Harley Davidson Street Glide CVO 117 CVO 2022
Harley Davidson Street Glide CVO 121 CVO 2023
Harley Davidson Street Glide ST 117 Touring 2022
Harley Davidson Street Glide ST 117 Touring 2023
Harley Davidson Hydra-Glide Revival 114 Softail 2024
Harley Davidson Freewheeler 114 Trike 2020
Harley Davidson Freewheeler 114 Trike 2021
Harley Davidson Freewheeler 114 Trike 2022
Harley Davidson Freewheeler 114 Trike 2023
Harley Davidson Freewheeler 114 Trike 2024
Harley Davidson Freewheeler 114 Trike 2025
Harley Davidson Softail Fat Boy Gray Ghost 117 Softail 2025
Harley Davidson Softail Fat Boy Gray Ghost 117 Softail 2026
Harley Davidson Road Glide 3 114 Trike 2023
Harley Davidson Road Glide 3 114 Trike 2024
Harley Davidson Road Glide 3 114 Trike 2025
Harley Davidson Road Glide 117 Touring 2024
Harley Davidson Road Glide 117 Touring 2025
Harley Davidson Road Glide 117 Touring 2026
Harley Davidson Road Glide Special 114 Touring 2019
Harley Davidson Road Glide Special 114 Touring 2020
Harley Davidson Road Glide Special 114 Touring 2021
Harley Davidson Road Glide Special 114 Touring 2022
Harley Davidson Road Glide Special Anniversary 114 Touring 2023
Harley Davidson Road Glide CVO 121 CVO 2023
Harley Davidson Road Glide ST 117 Touring 2022
Harley Davidson Road Glide ST 117 Touring 2023
Harley Davidson Softail Street Bob 117 Softail 2025
Harley Davidson Softail Street Bob Solo 117 Softail 2026
Harley Davidson Softail Street Bob 114 Softail 2021
Harley Davidson Softail Street Bob 114 Softail 2021
Harley Davidson Softail Street Bob 114 Softail 2022
Harley Davidson Softail Street Bob 114 Softail 2023
Harley Davidson Softail Street Bob 114 Softail 2024
Harley Davidson Softail Breakout 117 Softail 2023
Harley Davidson Softail Breakout 117 Softail 2024
Harley Davidson Softail Breakout 117 Softail 2025
Harley Davidson Softail Breakout 117 Softail 2026
Harley Davidson Softail Breakout Anniversary (ANX) 114 Softail 2018
Harley Davidson Softail Breakout 114 Softail 2019
Harley Davidson Softail Breakout 114 Softail 2020
Harley Davidson Softail Breakout 114 Softail 2021
Harley Davidson Softail Breakout 114 Softail 2022
Harley Davidson Softail King 114 Softail 2019
Harley Davidson Softail King 114 Softail 2020
Harley Davidson Softail Fat Bob 114 Softail 2018
Harley Davidson Softail Fat Bob 114 Softail 2019
Harley Davidson Softail Fat Bob 114 Softail 2020
Harley Davidson Softail Fat Bob 114 Softail 2021
Harley Davidson Softail Fat Bob 114 Softail 2022
Harley Davidson Softail Fat Bob 114 Softail 2023
Harley Davidson Softail Low Rider S 114 Softail 2020
Harley Davidson Softail Low Rider S 114 Softail 2021
Harley Davidson Softail Low Rider S 117 Softail 2022
Harley Davidson Softail Low Rider S 117 Softail 2023
Harley Davidson Softail Low Rider S 117 Softail 2024
Harley Davidson Softail Low Rider S 117 H.O. Softail 2025
Harley Davidson Softail Low Rider S 117 H.O. Softail 2026
Harley Davidson Softail Low Rider ST EL Diablo 117 Softail 2022
Harley Davidson Softail Low Rider ST 117 Softail 2023
Harley Davidson Softail Low Rider ST 117 Softail 2024
Harley Davidson Softail Low Rider ST 117 H.O. Softail 2025
Harley Davidson Softail Low Rider ST 117 H.O. Softail 2026