Some time ago I posted a question concerning a "clunking" noise coming from the drive train. At the time I sort of thought it was a bad cutlass bearing. The boat has been sitting at dock for the majority of the season, and there is a lot of growth. Just the other day I ran the engine (in gear) at the dock to generate the noise and try to more specifically locate it. It's definately coming from aft of the stuffing box. It sounds like something slapping the hull. I took a look, as best I could from the dock, and saw a HUGE amount of barnicles and growth on the prop, but nothing obvious slapping the hull. Here's the question... Can this build up on the prop be causing this noise? Is this from cavitation caused by barnicles? I'm considering having a diver clean the prop as best he can and see if this will remedy the situation. I wasn't planning on hauling for the off season but rather, opting for in-water storage. My guess is that a diver would be cheaper than a haul. Any suggestions as to what else could be causing this noise? HELP!! Thanks!
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Could be
I get such a noise when my prop is clogged with barnacles. I suggest you clean the prop yourself. Take a heavy wood or plastic handled scraper, a deep breath of air, and whack them, then scrape them clean. Should be able to do a decent job in a few dives. It's less than a foot or so down and you can hold onto the shaft with your other hand. Then do the shaft. You can get it clean enough to get the shaft and prop back in balance. Make sure you have good protective gloves on. Barnacles are like razors.
I get such a noise when my prop is clogged with barnacles. I suggest you clean the prop yourself. Take a heavy wood or plastic handled scraper, a deep breath of air, and whack them, then scrape them clean. Should be able to do a decent job in a few dives. It's less than a foot or so down and you can hold onto the shaft with your other hand. Then do the shaft. You can get it clean enough to get the shaft and prop back in balance. Make sure you have good protective gloves on. Barnacles are like razors.
Go For The Diver
I would have the diver clean the prop and see what difference it makes ,I haul my boat every year and I clean the prop and shaft while its on the hard plus put new zincs on. I know that a clean bottom plus clean prop makes a big difference in a smooth running engine. nick
I would have the diver clean the prop and see what difference it makes ,I haul my boat every year and I clean the prop and shaft while its on the hard plus put new zincs on. I know that a clean bottom plus clean prop makes a big difference in a smooth running engine. nick
Maybe Something Else
It's possible that something else is wrapped up on the shaft. A possibility would be a line with the loose end tapping the hull when in gear at low speed. Otherwise, I would bet the barnacles are causing a problem. Have a diver scrape them off with a window scraper, paint scraper or a knife.
It's possible that something else is wrapped up on the shaft. A possibility would be a line with the loose end tapping the hull when in gear at low speed. Otherwise, I would bet the barnacles are causing a problem. Have a diver scrape them off with a window scraper, paint scraper or a knife.
sometimes
the zinc wear unevenly and break. The shaft is off balance for a while until maybe the whole thing breaks off. It happened to me for a while this summer and then it was fine. I hauled the boat out yesterday and the shaft zinc is gone!! ( Now I gotta figure out why)
the zinc wear unevenly and break. The shaft is off balance for a while until maybe the whole thing breaks off. It happened to me for a while this summer and then it was fine. I hauled the boat out yesterday and the shaft zinc is gone!! ( Now I gotta figure out why)
PROBLEM SOLVED...ALMOST
Well, thanks to all of your advice I had a diver inspect the undersides (the water is a bit chilly without a wet suit). He said there were a LOT of barnicles and growth on the shaft and prop. He cleaned it all up (including the engine water intake) for $50. A heck of a lot cheaper than having it hauled ($350 for two hours dry time). As soon as he left I cranked up the engine and found that "most" of the noise had gone. Instead of the rhythmic "clunking" sound, now it's more or less of a vibration with a low pitch rattle. Strange thing is, it's definately there in forward gear, but not in reverse. This doesn't make sense to me. Anyway I'm planning on having the yard look at it over the off season. Anybody have any idea what that noise is? My best guess is back to the cutlass bearing. Thanks all!
Well, thanks to all of your advice I had a diver inspect the undersides (the water is a bit chilly without a wet suit). He said there were a LOT of barnicles and growth on the shaft and prop. He cleaned it all up (including the engine water intake) for $50. A heck of a lot cheaper than having it hauled ($350 for two hours dry time). As soon as he left I cranked up the engine and found that "most" of the noise had gone. Instead of the rhythmic "clunking" sound, now it's more or less of a vibration with a low pitch rattle. Strange thing is, it's definately there in forward gear, but not in reverse. This doesn't make sense to me. Anyway I'm planning on having the yard look at it over the off season. Anybody have any idea what that noise is? My best guess is back to the cutlass bearing. Thanks all!
could be
If your prop and shaft have been cleaned and you still have a vibration. it may also be your strut bearing. you have to go under the boat grab the shaft and shake it if you hear anything or feel any play in the shaft, that's you problem. I had this happen to me.
If your prop and shaft have been cleaned and you still have a vibration. it may also be your strut bearing. you have to go under the boat grab the shaft and shake it if you hear anything or feel any play in the shaft, that's you problem. I had this happen to me.
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