YAMAHA KEY 664-44338-00

Function and technical context

The key is an essential mechanical fixing element in the engine's power transmission system, responsible for ensuring the connection between the shaft and rotating components such as propellers, pulleys or gears. It works at the heart of the drivetrain, preventing relative slipping between parts subjected to intense rotational forces. A failure or loss of this part causes misalignment or detachment of the attached component, resulting in total loss of propulsion, cascading damage to the drive system and risk of navigation.

When to replace this part?

The key requires visual inspection at each seasonal inspection, especially after grounding, impacts or abnormal changes in engine vibration. Symptoms of wear include excessive play in the joint, metallic rubbing noises in the shaft, or inability to transmit power correctly to the propeller. It is recommended to replace it preventively if it presents partial fractures, deformation or visible corrosion, since a breakdown during navigation can leave the boat without propulsion in critical situations.

Equivalent manufacturer part numbers