+.010in. Pistons with 8.5:1 Compression Ratio. Fits Big Twin 1941-1979 with 1200cc Engine.

Features & Benefits:-

* Bore=3.447"

* Stroke = 3.969"

* 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 # 22143-55

* Replaces OEM # 22143-74

Tech Tips:-

* 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.