Replacing propeller shaft cooling hose barb Beneteau 305

[jviss]

Looking at your photos, the new barb appears to be NPT threaded and the nut appears to be straight thread. If that is the case you are going to either have to find a straight threaded hose barb, or a pipe threaded nut. Otherwise its unlikely that you will be able to get a good seal.

Exactly.

 

[Alfa]

Hi Salty Tradewind,
I'm late with my comments; been away. Assume that your Beneteau First 305 (like other First I have seen) has cutless baring in the strut. If that's the case, you do not need any barb fitting or hose connected to stern tube because aft end of the tube is open admitting water to shaft seal for lubrication. All you have to do is to vent trapped air in the shaft seal and inject grease between two lip seals as per Volvo instruction.

Volvo-Penta shaft seal as well as PSS packless shaft seal are designed for installation bellow the water line; they need hydrostatic pressure to affect the seal and to lubricate.

In Oceanis series, cutless bearing is installed in the aft of the stern tube therefore sufficient water for lubricating both, shaft seal and cutless bearing, is supplied via hose from trough hull or engine heat exchanger drain port. In B First it is just unnecessary risk to have fitting, especially brass, in the stern tube.

316 Stainless Steel barb 3/8" hose - 1/8" NPT pack of 5, is available from Amazon.ca for $9.99 CAD.

NPT pipe thread and BSP (British Standard Pipe) thread can be parallel an tapered. Do not mix.
NPT has 60, BSP 55 degre thread, they are similar in dia, often different pitch. Should not be mixed.