NUT 90171-16011 REC90171-16011

Function and technical context

This nut plays a vital role in securing and securing critical marine engine components, ensuring the structural integrity of vital systems such as the cylinder head, crankcase or exhaust flanges. Its correct tightening guarantees that the mechanical elements remain solid under vibration, pressure and extreme thermal changes typical of the operation of Yamaha and Mercury propellers. Progressive loosening due to vibration or corrosion can cause coolant leaks, water infiltration, loss of compression or misalignment of components, compromising the reliability of the boat in navigation.

When to replace this part?

It is advisable to inspect the condition of this nut during each seasonal maintenance check, especially after repairs that involve dismantling the fixing area. If you detect corrosion, deformation of the thread, inability to tighten or recurrent loosening after retightening, it must be replaced immediately to avoid sealing problems or breakdowns while navigating. Preventive replacement in overhaul work guarantees the long-term durability and safety of the system.

Equivalent manufacturer part numbers