Std Flat Top Pistons with 9.0:1 Compression Ratio. Fits Sportster 1986-2021 with 1200cc Engine & Sportster 1986-1987 with 1100cc Engine. - Keith Black Pistons

* Bore=3.498" - Stroke=3.812

* Hypereutectic Alloy is a cast 16% silicon content material

* Perfect for air cooled engines

* Low thermal expansion rate = tighter piston-to-cylinder clearance

Tech Tips:-

* 9.0:1 Compression Ratio with 69cc Head Chamber Volume.

* Follow Ring End Gap & Piston to Cylinder Clearances as per the supplied Manufacturers Instructions.

* Pull the engine down first & measure the existing bore to determine if oversize pistons are required PRIOR to purchase, we do not take back piston kits. The onus is on the assembling technician to validate the cylinders & required pistons.