[C320-list] noise at 1800

[Doug Treff]

I had a similar problem last year after having a new packing installed. 
Eventually it went away. Do keep an eye on the packing nut and make sure 
it's dripping at the specified rate to keep the packing cool.

---
Doug Treff
doug at treff.us

On 2013-09-03 07:13, jim brown wrote:
> Thanks Karl. I did have the prop treated. I had a similar issue with
> the two blade prob but it sounded less "screaming" than the sound I
> hear now-guess it might with another blade rotating around. I'll live
> with it unless the yard will haul for free to take a look since it
> wasn't there before the work was done. As an aside. we met Orlando in
> Oriental when he was poking around the yard where our boat was hauled.
> Had a nice chat. He very much enjoyed his stay and your hospitality.
> 
> Once again membership in the Association has more that paid for 
> itself.
> 
> Jim Brown
> 
> 
> 
> ________________________________
>  From: Karl Mielenhausen <kmielen at suddenlink.net>
> To: C320IA Discussion List <C320-List at catalina320.com>
> Sent: Monday, September 2, 2013 9:53 PM
> Subject: Re: [C320-list] noise at 1800
> 
> 
> Did you have any bottom paint or other anti-fouling treatment applied
> to the prop?
> When I did, I developed a similar sound which occurs only at specific 
> rpms.
> The problem usually is a result of a fine trailing edge on the blades.
> There is past discussion here...
> http://lists.catalina320.com/pipermail/c320-list-catalina320.com/2010-September/033709.html
> 
> Bottom line... there is no eminent mechanical failure, so you can live
> with it until the next haulout.
> 
> BTW, an alignment issue could sound like you have a loose chain
> rotating around the propshaft, wrapping against the hull.
> 
> Karl
> 
> On Mon, Sep 2, 2013 at 7:00 PM, jim brown <jbrown5093 at yahoo.com> 
> wrote:
>> Had the boat hauled while we were on vacation for a week to have the 
>> bottom cleaned and repainted. While it was out I had the two blade 
>> prop changed to a three blade (my wife is at the helm and wanted more 
>> reverse power-I know it's slower-she doesn't care), the cutlass 
>> bearing replaced (10 years on the original) and the stuffing gland 
>> redone with Gortex packing. When taking the boat back to our marina we 
>> noticed a high pitched screeching sound only at 1800 to 2200 rpm. Go 
>> below 1800 and above 2200 and no vibration and quiet. No noise at the 
>> dock in neutral throughout the rpm range. Can't really locate the 
>> noise except it doesn't seem to be coming from the transmission or the 
>> packing gland (and that is cool after half hour of motoring), and it 
>> seems a little louder in the aft lazarette.   Any suggestions? Is 
>> there an upper bearing in the stuffing box that might need attention?
>> 
>> Jim Brown  Desafinado 973
>> 
>> 
>> 
>> ________________________________