SCREW M6X40

Function and technical context

This M6×40 screw is part of the structural fastening elements on Yamaha and Parsun outboard motors, ensuring the fixation of critical components of the engine block and auxiliary systems. Its function is to hold together parts subjected to constant vibrations and temperature changes typical of the operation of marine propulsion. A worn, corroded or poorly tightened screw can cause loosening of components, loss of tightness in joints, entry of salt water into sensitive areas and, in serious cases, misalignment of internal parts that compromise the performance of the engine.

When to replace this part?

Set screws on marine engines require regular inspection due to accelerated corrosion caused by ambient salinity and continuous vibration of the operating engine. It is recommended that these items be checked and, if necessary, replaced at each seasonal maintenance, especially after using the engine in salt water or after prolonged periods of inactivity. Preventive replacement of corroded or damaged screws prevents costly emergency repairs at sea and ensures the structural integrity of the engine throughout the sailing season.

Equivalent manufacturer part numbers