KEITH BLACK PISTONS Std Flat Top Pistons with 8.6:1 Compression Ratio. Fits Big Twin 1984-1999 with Evo Engine.

Description

Features & Benefits:-

* Bore = 3.498in.

* Stroke = 4.250in.

* Hypereutectic Alloy is a cast 16% silicon content material.

* Perfect for air cooled engines.

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

* Complete kit includes: two pistons, rings, wrist pins and clips.

* Replaces OEM # 21940-83

Tech Tips:-

* 8.6:1 Compression Ratio with 80cc Head Chamber Volume.

* Follow Ring End Gap & Piston to Cylinder Cle