Transmission "whistling" B331 Yanmar 3GM

[Bluenose]

Hi there, we took our B331 out for the first sail of the year. We stopped the motor and the shaft was spinning like it always does. Except it was making a fairly loud whistling sound. Could be heard from the cockpit. We returned with the motor on and sure enough at about 2100 RPM it was back. Less than 700 hours on the boat. Any thoughts?

 

[JoeWhite]

Growth of sea shells on the propeller. Do you hear that if sailing with motor turned off and gear in reverse?

 

[Jentine]

Have you determined that the sound is from the transmission? My guess is that it is from the propeller. I had the same problem several years ago. The prop would emit a squeal at a certain rpm. I took the prop to a prop shop and was told that it is a common problem and they knurled the outer edge of each blade. The problem ended.

 

[Bluenose]

Interesting, and thanks for replying. I changed the T-oil and made sure it was not overfilled. It comes in around 1,000 RPM and stops at about 1,400. I used to own an Island Packet and I am still on their site. This was mentioned there as well. I can't do anything until I am out of the water in the fall. I am comfortable sailing the season as it is not a mechanical grinding sound at all.