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Old 05-09-2006
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Why does my prop keep spinning?

Hello All,

On my Cheoy Lee 44, when I raise the sails and kill the engine, the prop starts spinning if I get over about 5 knots. I've tried shifting into forward and/or reverse, but it has no effect whatsoever-- the prop keeps spinning. The engine is a 50HP Perkins 4.108 Diesel and the transmission is a Borg Warner Velvet Drive.

I know this can't be good on the bearings and the packing gland. Any advice on how to stop this?
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Old 05-10-2006
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Have heard of shaft brakes to stop spinning and save rear trans bearings. Do a google search and something should show up. Know that articles have been written on the subject.
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Old 05-10-2006
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Why does my prop keep spinning?

Hi all
At 5kns the rotary moment indused by the draging force seams big enuff turning whatever holds your prop. So if you need a brake just for (against) that purpose, have a look at Kobelt Marine stuff etc.
If a free spinning prop would abuse your bearings you better get an other type! What do think a bearing has to stand when motoring day be day for years. By the way: fill up your accumulators using the drag by cuppling an generator to your prop shaft (see jareds adwise)
good luck elena http://www.kobelt.com/pdf/brochure_brake.pdf

Last edited by Ele5; 05-11-2006 at 11:49 AM.
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Old 05-10-2006
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Check to find out if letting the prop freewheel is bad for your transmission. For some it is, for others it is not. If your transmission doesn't care, then letting the prop freehwheel probably puts less drag on your boat and is a good thing. If not, the shaft brake is not unusual or complicated.

One other option, if your transmission can take the freewheeling, would be to attach a generator to the prop shaft. That way you leave it freewheeling, and it charges up the batteries for you!
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Old 05-10-2006
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I cannot concieve of any situation where a spinning prop is a good idea. Movemoent = wear.

Vice grip on the shaft?
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Old 05-10-2006
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A folding prop would also solve your problem. I don't know about your access, but vise grips on and off the prop (emergency - need to "hit the key") would be a pain for me.

Larry
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Old 05-11-2006
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The manual for my Universal diesel engine indicates that it is o.k. to leave it in neutral while sailing, so I was going to do that. But the manual for my Varifold folding propeller says I have to put it in gear to have the propeller fold up. So given these conflicting directions, what would you all recommend--in neutral or in gear? Would there be any disadvantage to keeping it in gear while sailing?
Thanks for any advice.
Frank.
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Old 05-11-2006
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You can not compare a fix prop with a foldable one! The first one reduces drag while spinning, the second by folding for less drag.
Stick your hand into the water while sailing and turn the hand 90° back and forth. You'll feel the difference!So what happens?

elena

Last edited by Ele5; 05-11-2006 at 12:01 PM.
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Old 05-11-2006
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Free Spinning Prop NOT a good thing...

A free spinning prop is not good. If for no other reason, it will slow the boat. Either put the transmission in gear or if hydraulic install a shaft break.
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Old 05-12-2006
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he Borg Warner boxes needs oil pressure from the input shaft, engine on. to engage the clutches. I guess your engine is not of the newest model, so has it been spinning this long, let it spin but keep the box in neutral position. It was not recomended by the older Borg Warner to let the propeller spin but a shaft lock to be innstaled, but as I said has it been spinning for the last 20+ years (?) I would keep on unless You plan a circum navigation.
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