Exmark 120-4288  Piston Pin Retaining Ring

The purpose of the Piston Ring is to wrap around a piston in order to seal the combustion chamber to ensure minimal loss of gases to the crankcase, improve heat transfer, maintain oil between the piston and cylinder wall, and regulate engine oil consumption. Damaged piston rings can create excess exhaust smoke and oil consumption, as well as impact the performance of the engine. Replacing a piston ring requires extensive disassembly of your equipment and engine.