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  Topic Review (Newest First)
05-02-2013 04:20 PM
Re: Strange noises from below...

We suggest movement that = more than 2.5% of shaft diameter as a worn bearing and one that should be changed. Different shaft sizes will run different clearances from new and different manufacturers also run different clearances so ideally you should get the spec from the manufacturer.
04-29-2013 11:53 PM
Re: Strange noises from below...

If you have a 3gmf like I do there is a spot between 1300-1700 rpm where it isn't as smooth, goes away after you power throught the range.
04-29-2013 10:08 PM
Re: Strange noises from below...

Ditto on the cutlass bearing.

04-29-2013 10:04 PM
Re: Strange noises from below...

I'll third the cutlass, and throw in an engine alignment/mounts issue as well.

No big deal, just routine maintenance issues.
04-29-2013 09:35 PM
Re: Strange noises from below...

cutlass bearing...hopefully you haven't damaged the shaft yet, if so it may need to be replaced as well. Looks like a dive or haulout
04-29-2013 08:52 PM
Re: Strange noises from below...

If you can feel it in your feet you most likely have an engine/shaft alignment issue and/or possibly a worn cutlass bearing. I don't no what the chirping is; hamsters?
04-29-2013 08:47 PM
Re: Strange noises from below...

Do you have frisky couples on board when you take the boat out?
04-29-2013 08:44 PM
Re: Strange noises from below...

After our last haul out for anti fouling in November our girl developed an odd thump thump when in reverse. This with a Flex-o-Fold prop. She was again hauled late March for another reason and while she was out I gave the prop a really good going over to make certain it opened all the way out and had no obstructions. Since going back into the water the noise/vibration has stopped. I am told it could have been cavitation caused by the prop not fully opening (possible something caught up inside) and went away after I had cleaned away the obstruction.

Soooo .... if you have a folding prop maybe same problem. If fixed prop simply ignore everything I have just said.
04-29-2013 08:41 PM
Re: Strange noises from below...


The thumping sound is a classic symptom of worn cutless bearing.

Good luck
04-29-2013 08:37 PM
Re: Strange noises from below...

I experienced a chirping noise like you described, and found it was a loose zinc on the propshaft. You may also want to check your cutlass bearing. If you have a folding prop, it may have some slop in the blades, or it may not be opening properly causing an imbalance.
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