Piston rings seal the gap between the piston and the cylinder of the STIHL 180 chainsaw: they hold compression and keep oil from getting into the combustion chamber unnecessarily. Manufacturer: EMAST.
Replace them if compression has dropped, there is hard starting, loss of power and bluish smoke. Choose the size by the piston diameter. Before installing, inspect the cylinder bore: if it is scored, the rings will not last long.
