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Prop and rudder

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Janet View Drop Down
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Post Options Post Options   Quote Janet Quote  Post ReplyReply Direct Link To This Post Topic: Prop and rudder
    Posted: 05 Jan 2010 at 9:19pm
When Jaywalker came out of the water in the autumn we were surprised to find a circular defect, a few mm deep, in the rudder gel coat opposite the Darglow prop anode. It looks at 1st glance as if the anode has ground into the leading edge of the rudder. No problem noticed with vibration, or suspicion of anything round the prop.
Prop date 2004. Volvo engine removed for rebuild, propeller serviced, and all professionally done just before we bought the boat in 2008.
Have a photo that could email.
Any ideas, please? Janet
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moongirl View Drop Down
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Post Options Post Options   Quote moongirl Quote  Post ReplyReply Direct Link To This Post Posted: 06 Jan 2010 at 7:38pm
Janet
I thinkthe first thing to dowould be to check that the propshaftis totally secure in the connection to the gearbox. It would seem unlikely that this would be the problem as if the connection was slack enough to allow the shaft to extend out to allow the anode to touch the leading edge of the rudder you would probably expect a loss of power - like a slipping clutch.
 
Colin
COLIN
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George Isted View Drop Down
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Post Options Post Options   Quote George Isted Quote  Post ReplyReply Direct Link To This Post Posted: 06 Jan 2010 at 8:48pm

Perhaps you had a rope or similar around the prop that caused this wear.  I had something similar, although only the removal of AF when caught some fishing net.  Perhaps you could ask the yard if they recall removing any debris from the prop after lifting.

George Isted
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Janet View Drop Down
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Post Options Post Options   Quote Janet Quote  Post ReplyReply Direct Link To This Post Posted: 14 Jan 2010 at 7:03pm
Thanks but it has not obviously been either of these causes but once the snow melts we'll be taking another look at the prop shaft inside the hull. Janet
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St Paddy View Drop Down
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Post Options Post Options   Quote St Paddy Quote  Post ReplyReply Direct Link To This Post Posted: 10 Feb 2010 at 2:23pm

Hi Janet

 

I think I know.

 

You have a feathering prop. This will have the same pitch in foward and reverse.  The propellor is flexing the engine mounts when in gear. The whole engine and shaft is pushing in and out of the boat, normally by about half an inch. This is nothing to worry about and is correct. Phone Darglow and ask for the anode that looks like a flat cap instead of the pointy type. They do sell them. This will give you more space. I have one in my draw

 

I assume you have a Yanmar 2GM as these have very soft mounts. The back ones might have failed. If it is covered in rust then it will most likely have broken the joint between the rubber and steel. Diesel fuel damages the rubber as well. Check for fuel leaks too.

 

On my boat I have a fancy unit called a Aquadrive this stops the problem and holds the shaft true and allowes the engine to do as it pleases.

 

Last but not least, do repair the gelcoat and keep the water out of your rudder.

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