NWP Big Bore Piston & Cylinder Assembly (56mm) for Stihl 066, MS650, MS660 Chainsaws

Big Bore cylinder assembly from NWP. Big Bore cylinder kits come with an oversized cylinder and piston (2mm), which will give your chainsaw increased displacement as compared to the stock cylinder. Cylinder assembly includes an oversized piston, rings, piston pin, circlips and cylinder. Cylinder bore is NiSi coated for long life. These pistons have a thin coat of molybdenum, which helps reduce friction and wear during the initial break in period. Piston rings are made from ductile cast iron, so your chances of breaking them during installation are greatly reduced. We recommend using a piston ring clamp set when changing your cylinder.

Important Note: Big Bore cylinder kits should be installed by professionals only, as some models may require slight crankcase modifications for fitment.