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S&S 1250 Big Bore Kit For Harley Sportster

Features:

  • S&S Cycle largest big bore kit for Sportster models that bolt to stock crankcases
  • Can typically increase horsepower to over 90hp with proper exhaust, camshafts, CNC ported heads, while using the stock fueling system
  • Forged pistons are dome top 11.2:1 compression ratio (based on 60cc combustion chambers)
  • Each piston is fitted with rings and wristpins, and have larger then stock valve pockets that accept up to 2.00″ valves
  • Cylinders are 3-9/16″, available in silver or wrinkle black finish and come with MLS head, base, and exhaust gaskets

Note: S&S Cycle cylinders match the 1986-2003 cylinder heads. 2004-15 have a slight difference in fin profile. Cannot run stock 883 cylinder heads with this kit

Made in the USA
Product Style J&P Cycles Item # Catalog Number Store Sku MFR. Product # Availability
Product Style Black / 10.3:1 Compression Ratio J&P Cycles Item #1181564 Catalog Number207-083 Store Sku MFR. Product #910-0691 AvailabilityIn Stock: Ships within 24 hours
Product Style 10.3:1 Compression Ratio / Silver J&P Cycles Item #1181565 Catalog Number207-082 Store Sku MFR. Product #910-0689 AvailabilityIn Stock: Ships within 24 hours
Product Style Black / 11.2:1 Compression Ratio J&P Cycles Item #1181566 Catalog Number207-085 Store Sku MFR. Product #910-0692 AvailabilityIn Stock: Ships within 24 hours
Product Style Silver / 11.2:1 Compression Ratio J&P Cycles Item #1181567 Catalog Number207-084 Store Sku MFR. Product #910-0690 AvailabilityOnly 3 Left: Ships within 24 hours
Please review this product's fitment notes & exceptions prior to purchase: Add to Cart
This product is vehicle specific.
Select a vehicle to ensure fitment.
Fitment Notes & Exceptions
  • Can not run stock 883 cylinder heads with this kit.
  • S&S does not recommend boring 2004 and later 883cc cylinders from 3" to 3-9/16" bore to increase engine displacement to 1250cc due to changes in factory cylinder and liner.
  • The cylinder fin profile does not perfectly match the fins on 2004 and later stock heads, but the difference is not considered to be objectionable.
  • See instructions for full details on installation.
This Product Fits
Harley Davidson
Sportster Custom XL1200C 1996-2019
Sportster Custom XL883C 1998-2009
Sportster Deluxe XLH883DLX 1989, 1990, 1991, 1992
Sportster Forty-Eight Special XL1200XS 2018, 2019
Sportster Forty-Eight XL1200X 2010-2022
Sportster Hugger XLH883HUG 1988-2003
Sportster Iron XL1200NS 2018, 2019, 2020, 2021
Sportster Iron XL883N 2009-2022
Sportster Low/SuperLow XL883L 2005-2019
Sportster Low XL1200L 2006-2011
Sportster Nightster XL1200N 2007-2012
Sportster Roadster XL1200CX 2016, 2017, 2018, 2019, 2020
Sportster Roadster XL1200R 2004, 2005, 2006, 2007, 2008
Sportster Roadster XL883R 2002-2012
Sportster Seventy-Two XL1200V 2012, 2013, 2014, 2015, 2016
Sportster Sport XL1200S 1996-2003
Sportster SuperLow XL1200T 2014, 2015, 2016, 2017
Sportster XL883 2004-2009
Sportster XLH1100 1986, 1987
Sportster XLH1200 1988-2003
Sportster XLH883 1986-2003

S&S Cycle 1250 Big Bore Kit For Harley Sportster 1986-2022 Instructions

Product Description
Part Numbers
Fitment
Instructions
4 Customer Reviews
4 4.5/5
10 Questions & 8 Answers
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