Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 05-06-2012, 11:58   #1
Registered User

Join Date: Jan 2010
Location: North Carolina
Boat: 1984 Pearson 34, Sirena
Posts: 32
Pounding and slamming prop sounds

I'm hoping some of you have some expereince with a problem that came up over the weekend.

My wife, the cats and I were returning from Ocracoke, NC leaving through Nine Foot Slough on a Pearson 34. The weather forcast was for 5-10 on the nose and it was 20 knots plus.

As we got to the area where the sound necks down to the shallows at Nine Foot, we entered some big waves. A set of 3 waves stopped the boat completely, we were hobby horsing badly. I was doing 5 knots before being stopped.

It sounded like the prop was hitting the bottom of the boat as we hobby horsed. I thought all hell was breaking loose. Couldn't shut the engine down or we would have ended up on the sand. As I got out of the pounding waves, turned and raised some sail, the prop pounding sound stopped. It sounded like it came from under the wheel or where the prop leaves the hull. I couldn't see any damage inside the engine compartment.

Thsi happened once before in the same conditions and I dove on the boat later, no visible damage.

So what can be causing the sound? The engine and transmission was new last year and was aligned. Is the cutless loose, worn? Just cavitation? It really did sound like the prop was hitting something on the boat.

We made it home with one seasick cat and I have more grey hair.

Dale
__________________

__________________
DaleM is offline   Reply With Quote
Old 05-06-2012, 12:02   #2
Registered User

Join Date: May 2012
Location: Central California
Boat: Catalina 30
Posts: 873
Re: Pounding and slamming prop sounds

Possibly cavitation.
__________________

__________________
Bill
...........................................
You can't buy happiness, but you can buy ribeye.
jongleur is offline   Reply With Quote
Old 05-06-2012, 12:05   #3
Registered User
 
Astrid's Avatar

Join Date: Oct 2008
Location: Northern British Columbia, part of the time in Prince Rupert and part of the time on Moresby Island.
Boat: 50-ft steel Ketch
Posts: 1,885
Send a message via MSN to Astrid Send a message via Yahoo to Astrid
Re: Pounding and slamming prop sounds

Sounds like it could be a worn cutless bearing or loose strut. Have you been over the side to take a look?
__________________
'Tis evening on the moorland free,The starlit wave is still: Home is the sailor from the sea, The hunter from the hill.
Astrid is offline   Reply With Quote
Old 05-06-2012, 13:03   #4
Registered User
 
bruce smith's Avatar

Join Date: Jul 2008
Location: puget sound/ caribbean
Boat: never wrecked a boat while awake or sober
Posts: 330
Re: Pounding and slamming prop sounds

Yes, Sounds like a worn cutlass to me also. When they wear, the hole becomes oblong, and usually the shaft rides in the end it wants to go in. When the boat slammed the waves, it may have forced it over to the other side. The cutlass will go out of round from an un aligned engine. Popping a new bearing in there without aligning the engine is just a temp fix. remove the stuffing box on the inside and be sure the shaft is in the center of the tube when aligning. It is possible ti "mike" the coupling , but still not be aligned. The engine is aligned to the cutlass bearing, not the other way around.
__________________
bruce smith is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 12:59.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.