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

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10.3:1 Compression Ratio

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$949.95

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Type: Finish:

Blemished/Refurbished

This item is available as a Blem/Refurb. These are items that cannot be sold as "New" merchandise and are limited to stock on hand. See the product details for a description of the product's condition.

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This product is legal in California only for racing vehicles which may never be used, registered or licensed for use upon a highway.

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

Instructions (pdf)

S&S 1250 Big Bore Kit For Harley Sportster

This kit converts 1200cc HD Sportster models to 1250cc displacement. No machining or rebalancing is required. Forged pistons have larger than stock valve pockets and accept up to 2.00" valves. Kit contains forged flat topped 3 9/16" bore pistons with coated piston skirts, S&S 3-9/16" bore cylinders, MLS head gaskets, base gaskets, exhaust gaskets, assembly lube, and instructions.

Features:

10.3:1 Flat Top Pistons
11.2:1 5.5cc Domed Pistons
Available in silver powder coat or wrinkle black powder coat finish
Made in the USA

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This product is vehicle specific. Click here to select your 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.

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, 1988; Sportster XLH1200 1988-2003; Sportster XLH883 1986-2003

Product Style	Item #	Store SKU	Manufacturer Product #	Availability
Product Style Black / 10.3:1 Compression Ratio	Item # 1181564	Store SKU	Manufacturer Product # 910-0691	Availability Available: Ships in 1-2 business days
Product Style 10.3:1 Compression Ratio / Silver	Item # 1181565	Store SKU	Manufacturer Product # 910-0689	Availability Available: Ships in 1-2 business days
Product Style Black / 11.2:1 Compression Ratio	Item # 1181566	Store SKU	Manufacturer Product # 910-0692	Availability Available: Ships in 1-2 business days
Product Style Silver / 11.2:1 Compression Ratio	Item # 1181567	Store SKU	Manufacturer Product # 910-0690	Availability Available: Ships in 1-2 business days