KB410040 Performance, 883-1200 big bore piston kit. +.040"

This KB Performance piston set is engineered for 1986 to 2022 XL883 models undergoing an 883 to 1200 conversion. These +.040" oversize pistons are flat-top designs that maintain a stock-style 9:1 compression ratio when used with unmodified 883 heads. Sold as a set, they are manufactured from T6 heat-treated 390 hypereutectic cast aluminum. The high silicone content allows for very tight piston-to-wall clearances, resulting in a quiet and durable engine. For owners of 2004 and later 883 Sportsters, please be aware that stock cylinders cannot be bored to 1200cc size; you will need to purchase 1200cc cylinders to use this kit. As with all KB Performance pistons, the top compression ring requires additional clearance for proper operation.