Things that go thump...namely props.

[Frank A.]

I have a 1992 Hunter 28 that I purchased last year. Boat is in outstanding like-new condition and I couldn't be happier with it. But I have one item that may be more "annoyance" than problem:When under sail, as soon as speed approaches 5.5-6.0 kt, there is a "thump-thump" sound continously. I've isolated it to the prop freewheeling because if I put the shift lever in reverse, the noise ceases. But it then costs me anywhere between .2 to .5 kt in speed. Shifting into forward minimizes the sound but it doesn't go away completely. The boat is equipped with the factory 18hp Yanmar engine.When commissioned this spring, shaft play, bearing play, etc were all within spec.More annoyance than anything else. Anyone else out there have a similar experience.????

 

[Nigel]

The Big Question

Frank- you have of course uncorked a wide controversey about whether to leave the prop in gear or freewheeling while sailing. I do keep mine in reverse when sailing in anything but a light zephyer. I have heard that freewheeling can potentially damage the transmission- you should check out the forum archives I bet there are a lot of posts about this subject

 

[Marc Honey]

Nature of the BEAST

Put that bad-boy in reverse and don't sweat the 1/2 knot that you might lose!!"Knot" much that you can do short of a folding prop!!!

 

[Alex]

sAME OM MY 29.5 / Yanmar

..Junt don't leave it neutral but lock it in reverse.

 

[Pete]

Reduce prop drag

You may be able to reduce prop drag by locking the prop in a vertical position. Takes crew of two. Believe that if you hold the prop shaft with the shaft key pin on top the other crew member can lock it in that position by putting it in gear. Now your prop will be in draft of your keel. Boat may be faster than when free wheeling the prop.