This kit converts 1986-'18 883cc and 1200cc HD Sportster models to 1250cc displacement. No machining or rebalancing is required. Kit contains forged 5cc pop-up 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. 883 cylinder heads may not be used with this kit. For the best performance CNC head porting, performance cams, exhaust and intake upgrades are recommended.
Can not run stock 883 cylinder heads with this kit.
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 Photos.
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. A smaller O.D. liner and large chamfer on the bottom of the spigot
make boring the 883 cylinder not possible. New cylinders are recommended.