Ok,
Before I changed the packing material in the packing gland, all was relatively quiet when the motor was running and in gear. I changed the packing material, ran it in for about an hour in gear at the dock and all was well.
Yesterday was the first sail since then. Now, when I put it in forward, there was a thumping sound. After getting under sail and shutting the engine down, I noticed the thumping noise was still there. I shifted out of neutral and into forward and the sound remained. However, when I shifted it to reverse, the sound stopped. Upon starting the motor again, the noises returned.
Any ideas guys?
I've noted that things that are hard to do on the internet are: sounds, smells and electrical pictures without wiring diagrams. :D
I don't think it has anything to do with your stuffing box. It could well be that your old stuffing was keeping your prop from spinning while you were sailing. Never sail with your transmission in forward gear, it's not good for the transmission. Use neutral, or, as we do, reverse. We get a rumbling sound when sailing with the gear in neutral, so we shift to reverse when the engine is off.
Stu,
I think rumbling is a better term for what I have. Do you hear it when in forward with the engine running?
Huth recommends neautral or reverse when sailing.
Ralph
Lance : You didn't mention if you have dripping from the packing gland and what the temperature of it is when running? HOT/warm/cold?? These are VERY important things to check after changing packing!!
As Stu mentioned noises are hard/impossible to accurately pass on to readers. You didn't mention where this noise was coming from? Have a stethoscope / or try a screwdriver handle to your ear?
A few thoughts in trying to help.
The rumbling sound that I heard when I first got my boat was a worn out cutlass bearing. (When this wears out the shaft vibrates in the strut.) It had been worn through in less than 40 engine hours because there was no water flow through it: it had been painted over with antifouling.
Thinking about how you described what you did: you ran the engine in gear at the dock for an hour. Is it possible that this overheated the cutlass bearing due to lack of water flow? Once overheated it quickly wears through...
Tony
Quote from: Lance Jones on May 02, 2011, 12:20:57 PM
Do you hear it when in forward with the engine running?
No 'cuz when the engine's running I don't hear anything else. :D :D :D
I never put it in forward when the engine is off.
There is great merit to what Tony suggests. Can't imagine why you ran the engine in gear for that long at the dock.
It says to run the engine for an hour and then readjust if needed. Prop shaft was not hot after running.
Lance, you might check your shaft zincs. I had a similar sound and it turned out to be one of the shaft zincs had loosened and slid down the shaft and was rubbing against the strut. You would not hear it in reverse as the prop is not turning.
Jack
Jack,
Good answer. Only I don't have zincs in fresh water and two, why wouldn't the prop turn in reverse?
Jack in reverse is a direct lock up in the transmission. no clutch pads. The PO of my boat had to back it all the way home when the clutch pads went out. Charlie
Lance,
You should still have a zinc in freshwater. Electrolysis is not nearly as bad as in saltwater, but (unless you're in distilled water) the potential (pun intended) is still there. Just a thought...
Ding, ding, ding, ding!!!!!!!!
Jack had the right answer all along. I humbly admit, I do have zincs and the one on the prop shaft had done exactly what Jack had suggested. Thanks for the answer Jack! :clap
That being said, I see there are three choices of metals to replace with - zinc, aluminum, and magnesium. Which of these is best for the prop shaft?
Good work.
On the tranny issue my reading of the Hurth materials indicates that when sailing they recomend the transmission be placed in reverse. Leaving it to spin all day in neutral was discouraged and in any event will create more drag then a stationary prop in reverse...think helicopter counter-rotation when it has to drop to the ground "sans" engine...that's french for "without".....our other official language up here.
Hawk
Thanks Hawk. I knew that about putting it in reverse when sailing. Your language comment made me think of when I took our Canadian rep out to Outback for dinner. When signing in to wait, the hostess asked, "How many?" I replied, "3 AND we would like the Canadian language section of the restaurant." She looked like her head went into a tailspin... She looked at the manager and asked.... "Do we have a Canadian language section?" The manager looked at me with a huge grin on her face and simply said, "Take pity on the pretty ones please, they're fragile...." :rolling
Loved it!
BTW Happy early Canada Day!
Thanks for the early best wishes Lance. As a proud Canadian, I love "Canadian" jokes.
i.e. Americans fought their way to independence from Britain. Canadians just bored the Brits to death and then asked "can we pleeeease leave now?" They were only too happy to be rid of us. (sort of)
It looks like a fantastic weekend here in the southern Ontario... and we enjoy sharing a long weekend on the International Great Lakes with our neighbours across the border this year... Happy 4th of July!!
I have heard that Magnesium is the best "zinc" for fresh water and zinc is the best zinc for salt. At least I hope so... I paid about 3x the price for magnesium over zinc this spring.
Thanks Dave!
Magnesium is sooooooo expensive.
As an Irish musician, I always ask the crowds if there are any Canadians out there. If there are, we have to play everything in the key of "A". If there are any Spaniards or Latin folks, we have to stick to "C".
New magnesium "zinc" installed on prop shaft!
Guys : I grew up on an inland lake in Wisconsin and we never had any electrolyse ( that I ever heard about) from/in fresh water!
I'm wondering if the magnesium diode manufactures made this up??