PISTON RINGS 0.25 YAMAHA 64D-11603-02

Function and technical context

The piston ring is an essential component of the compression system in Yamaha four-stroke engines. Its main function is to guarantee sealing between the piston and the cylinder walls, preventing combustion gases from leaking into the oil pan. These rings work under extreme conditions of temperature and pressure, performing continuous reciprocating movements during engine operation. Wear in the piston rings causes a progressive loss of compression, a decrease in power, an increase in fuel consumption and entry of oil into the combustion chamber, which accelerates the general deterioration of the engine.

When to replace this part?

Symptoms of piston ring wear include loss of engine power, difficulty in cold starting, bluish smoke emission from the exhaust due to oil burning, and abnormal increase in the oil level in the crankcase due to fuel contamination. Although there is no fixed maintenance interval, checking the rings is especially recommended after long hours of operation or if a significant drop in cylindrical compression is detected. The preventive replacement of the rings when overhauling the engine prevents secondary damage to cylinders and pistons, guaranteeing the reliability of propulsion in navigation.

Equivalent manufacturer part numbers