NUT 90179-09M02 REC90179-09M02

Function and technical context

This nut is part of the engine's structural fastening systems, ensuring the safe closure of critical components in the mechanical architecture of Yamaha and Mercury engines. Its function is to keep the assembled elements under constant clamping pressure, avoiding vibrations and misalignments that would compromise the tightness and correct functioning of adjacent joints and systems. Failure or loosening of this nut can cause loss of tightness in cooling, exhaust or lubrication pipes, with the risk of water entry or loss of vital fluids during navigation.

When to replace this part?

It is advisable to check the condition of this nut during each seasonal maintenance, especially if it has been exposed to prolonged vibrations or heating-cooling cycles that favor progressive loosening. Symptoms of malfunction include abnormal engine vibration, small leaks around the fastening area, or findings of loose nuts during visual inspections. Replacing it preventively when carrying out major maintenance prevents emergency repairs at sea and ensures that the sealing systems maintain their integrity throughout the sailing season.

Equivalent manufacturer part numbers