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

Description

* Bore=3.498in. – 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