PISTON RING KIT 0.25 YAMAHA 61N-11604-00

Function and technical context

The piston rings are part of the compression and sealing system of the Yamaha marine engine, located in the piston grooves to guarantee the tightness of the combustion chamber. Its main mission is to prevent the leakage of combustion gases into the crankcase and control the oil film on the cylinder walls, thus maintaining the pressure and efficiency of the expansion process. The accelerated wear of these components causes loss of compression, increased fuel and oil consumption, as well as a notable decrease in available power. Poor ring functionality also generates gas entry into the lubrication system, compromising the integrity of the engine oil.

When to replace this part?

Symptoms of deterioration include bluish smoke in the exhaust, increased oil level in the crankcase with dilution, progressive loss of maximum revolutions and difficulty starting when cold. Piston rings should be checked during each seasonal maintenance and replaced preventatively upon reaching the manufacturer's recommended operating hours or if there is evidence of low compression in specific cylinders. Preventive replacement in this kit is the best guarantee to avoid costly cylinder damage and maintain engine reliability while underway.

Equivalent manufacturer part numbers