+.010in. Flat Top Pistons with 8.6:1 Compression Ratio. Fits Big Twin 1984-1999 with Evo Engine. - Keith Black Pistons

Features & Benefits:-

* Bore = 3.508"

* Stroke = 4.250"

* 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 # 21942-83

Tech Tips:-

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

* Follow Ring End Gap & Piston to Cylinder Clearan

ces 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.