NWP Piston Assembly (54mm) for Stihl 066, MS660 Chainsaws (Replaces 1122 030 2005)

Replacement big bore piston assembly for NWP. These piston assemblies are designed to fit NWP big bore kits only, and will not fit standard OEM cylinders. Piston assembly includes an oversized piston, rings, piston pin and circlips. Pistons have a thin coat of molybdenum on the skirt, which helps reduce friction and wear during initial break in period. The piston rings are made from ductile cast iron, so your chances of breaking them during installation are greatly reduced. We recommend replacing your cylinder gaskets and using a piston ring clamp set to help when changing a piston. Gaskets are sold separately.