PISTON SEGMENT RINGS 39-831255A6

Function and technical context

Piston rings are essential components of the compression system in Mercury, Mariner and MerCruiser marine engines. These metal rings are installed in the piston grooves and act as dynamic seals, maintaining compression pressure within the combustion chamber and preventing gases from escaping into the crankcase. They work under extreme temperature and pressure conditions, guaranteeing the necessary tightness for the engine to generate the required power. Wear or breakage of the rings causes loss of compression, excessive oil consumption, smoke in the exhaust and significant reduction in engine performance.

When to replace this part?

Piston rings should be checked and inspected during each seasonal maintenance, especially in engines with high operating hours or that show symptoms such as abnormal oil consumption, loss of compression, difficult starting or bluish emissions. Preventive replacement is recommended during a general engine overhaul or if visible wear is detected during maintenance tasks. Changing these components preventively avoids costly repairs and the risk of failure in the middle of the water.

Engine Compatibility

Compatible Mercury Mariner Engines

Equivalent manufacturer part numbers