SKEG YANMAR

Function and technical context

The skeg is the protective fin located at the bottom of the tail of the outboard or inboard engine, in front of the propeller. Its main function is to protect the propulsion system against impacts with the bottom, rocks or submerged objects, acting as the first line of defense for the shaft and propeller in the event of a collision. In Yanmar engines, this component is an integral part of the lower unit and also contributes to the hydrodynamic stability of the boat during navigation. A damaged, cracked or torn skeg directly exposes the propeller shaft to impacts that can cause it to bend, damage the stern tube seal or compromise the alignment of the drive system, which can lead to high-cost repairs.

When to replace this part?

The most common symptoms that indicate the need to replace the skeg are: visible deformation or partial breakage after an impact with the bottom, loss of material in the fin, longitudinal or transverse cracks detected in the visual inspection of the engine tail, and abnormal vibrations during navigation that are not explained by propeller imbalance. It is recommended to inspect the skeg at each seasonal tune-up and especially after any running aground or sailing in shallow water. Replacing it preventively as soon as structural damage is noticed prevents a subsequent impact from directly reaching the propeller shaft, saving a significantly more expensive repair in a nautical workshop.

Equivalent manufacturer part numbers