Bukh DV20 strange(?) noise

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webber63

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Hi everybody
A few weeks ago I was worried by a certain noise coming from the 'Raised Hand Start', ie the casing containing the chain that leads the movement to the water pump and the hand starting mechanism.

I bought bushings, bearings and a new chain from the Italian Bukh distributor and overhauled it.
Unfortunately I still feel something strange:
The noise seems that of a chain that runs with some play, but I checked the measurements and according to the specifications of the manual they are correct.

Is there someone who has the DV20 and that had experience about this issue or can tell me if what you feel may be normal?

Thank you all

Francesco
 
I haven't had such an issue although I did have to replace the pump and bearings last year when the sump started to fill with water! There certainly was quite a bit of play in the chain although I don't recall a great amount of noise. Are you certain that is where it emanates from? Is there any sign of wear on the inside of the casing? If the chain was loose enough I'd expect it to damage the metal.
 
Thanks for your reply, Champagne Murphy
There was no wear and no sign of water inside.
The pump has been overhauled, too.
I'm considering to take apart the casing from the engine and make it turn somehow to be sure the noise is coming from there, although I'm almost sure it does come from it.
 
Perhaps check the valve clearances first, its easy to do and probably a common cause of noise. Bukh engines are not the most finely engineered but they are certainly 'over' engineered so whilst not quiet they are usually reliable and durable.
 
I'm currently experiencing the same problem on Bukh 24. Rattle seems to be coming from behind waterpump which I assume is the starter chain which I have ready to replace. Unfortunately 3 bolts have corroded heads so was unable to do as I couldn't get the casing off. Been using the boat and I've noticed some days it's noisier then others but part from rattle everything seems ok. One thing I did notice was on turning the Seacock off last weekend it was warm to touch again, and so was the waterpump. Could anyone enlighten me as to why this would be the case?
 
Pords said:
I'm currently experiencing the same problem on Bukh 24. Rattle seems to be coming from behind waterpump which I assume is the starter chain which I have ready to replace. Unfortunately 3 bolts have corroded heads so was unable to do as I couldn't get the casing off. Been using the boat and I've noticed some days it's noisier then others but part from rattle everything seems ok. One thing I did notice was on turning the Seacock off last weekend it was warm to touch again, and so was the waterpump. Could anyone enlighten me as to why this would be the case?
Click to expand...
Impeller blades u/s allowing backflow ?????
 
sailorman said:
Impeller blades u/s allowing backflow ?????
Click to expand...
Thanks Sailorman. I did order a new impeller today as I thought this might be the case. Impeller has only had 25 hours running mind and was new at the beginning of the season. Will change anyway as a precaution.
 
webber63 said:
This issue is driving me crazy.
For corroded bolt heads I use this tool:
http://www.ebay.it/itm/Usag-458-Est...ezzati-/262488439782?var=&hash=item3d1d87bbe6
You can find it in several sizes.
Just drill a suitable hole on the head of bolt, It's amazing how can be straightforward to remove seized bolts otherwise almost impossible to unscrew.
Click to expand...

I guess we all use those .... often called Easy-Outs although I call them reverse thread extractors. However, they need to be used with care as if the bolt or stud is really corroded in and the extractor snaps, easier with the smaller sizes than with large of course, then you are in a world of pain. :ambivalence:

Richard
 
You should ring the guys at Bukh UK in Poole. It seems to be run by 2 guys who know everything there is to know about Bukhs, they can talk you through how to do all sorts of repairs and have even typed up some helpful instructions for some parts.
Regards
 
VicS said:
It looks rather loose to me!

If that's a new chain then I'd suspect that the sprockets are worn.
Click to expand...
Yes but with the cover removed the upper shaft is not supported at its front end.

I wonder if webber63 has inspected the bearing at the back of the upper shaft. If that is worn it could account for the noise he hears
 
Onia said:
You should ring the guys at Bukh UK in Poole. It seems to be run by 2 guys who know everything there is to know about Bukhs, they can talk you through how to do all sorts of repairs and have even typed up some helpful instructions for some parts.
Regards
Click to expand...

Al and Norm have retired fairly recently. I'm not sure that the replacement has quite the depth of experience that they had. Their sense of humour was quite something too!
 
parsifal said:
Yes but with the cover removed the upper shaft is not supported at its front end.

I wonder if webber63 has inspected the bearing at the back of the upper shaft. If that is worn it could account for the noise he hears
Click to expand...
Yes, I have serviced the whole unit with new bearings, bushings, chain etc.
Then only elements I didn't change are the sprockets.
And I'm afraid their price is "quite something too!" :)
 
webber63 said:
Yes, I have serviced the whole unit with new bearings, bushings, chain etc.
Then only elements I didn't change are the sprockets.
And I'm afraid their price is "quite something too!" :)
Click to expand...
I'd be very surprised if the sprockets were worn to any appreciable extent. All that chain does is drive a water pump and, if I remember correctly, transmit your muscle power from the starting handle to the camshaft.

But an inspection of the sprocket teeth will soon show if they are 'hooked' on one side, which is what happens to them when they wear. Here's a photo showing what I mean:

https://www.google.co.uk/search?q=w...UICCgC&biw=1280&bih=800#imgrc=vlVs5j54ctafHM:
 
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Pords said:
Thanks Sailorman. I did order a new impeller today as I thought this might be the case. Impeller has only had 25 hours running mind and was new at the beginning of the season. Will change anyway as a precaution.
Click to expand...

If you've already changed the impeller recently then it should be OK. A more likely cause might be wear on front and rear faces of the pump. I had that on my old DV20 many years ago and was told that it was quite common. It made the pump slow to prime as air leaked back past the impeller faces (not the vanes). I found that it helped a lot if I turned the seacock off immediate after stopping the engine and only turning it on when I was about to start. This kept the pump pretty well primed most of the time.
 
It's a shame they have retired, I found them very helpful indeed. As for prices I'm not sure they were any worse than Volvo, and of course are no doubt increasing right now due to weak sterling.
 
What you could do, webber, is to eliminate as many sources of noise as possible. This will make it easier to listen to the noise that's worrying you, it may even disappear, indicating the noise wasn't coming from where you thought!

Take off the alternator belt and remove the water pump. Run the engine and try to locate the source of the noise using a long screwdriver as a stethoscope. Put the end of the handle against your ear and apply the business end to the engine in various places.
 
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