Bukh DV20 Exhaust elbow

joyfull said:
Excellent. Mine is running ok. I have given up on the thermostat for this year.

Not much water passing through, though I have only had the boat since last year so I do not know what to expect. It spits away and occasionally throws out a bit more. If yours in the water and back running maybe you could confirm how much to expect. I am not sure if the forum takes videos as it always asks me to compress my still pixs. I guess a link to vimeo or YouTube upload would work. I will try from my end.
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It is never a constant stream of water, nothing or spitting and then a big glug and nothing again. I believe this is because the exhaust pressure needs to build up enough to force through the water sat in the low point at the silencer. Long as its periodically throwing out about a large cupful its all good.
 
ScillyPuffin said:
It is never a constant stream of water, nothing or spitting and then a big glug and nothing again. I believe this is because the exhaust pressure needs to build up enough to force through the water sat in the low point at the silencer. Long as its periodically throwing out about a large cupful its all good.
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Exactly that, spitting away and then a big glug, then spitting away again. That's good news. Thank you for the feedback.
 
With my Kiwi boat fitted with a DV 20 I installed a silencer. The main pipe from the elbow to the outlet was 50mm. It exited through a simple Vetus water trap with 50mm connectors. I deleted the water trap, put in a reducer, 50mm to 32mm to join my new silencer, ditto the outlet.

The reduced diameter gives a much more satisfying squirt out of the transom. Before at idle it was little more than a dribble.
 
joyfull said:
The supplier French Marine haven't replied yet. But since yours arrived same as mine there probably isnt one
Also today bought spring washers for the flange as they were not there when I removed it, but are shown in the diagram. They are stainless as brass springs to match the nuts would be a bit pointless I thought as they would compress with no spring left. Did you find any washers when you removed your flange (if you had to remove it like I did because the whole assembly was solid.

I am about to do this job too. What size are the spring washers please? I reckon I'll need new ones.
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Poignard said:
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My cables have these spring clips but a clevis pin with split pin would do. So would a screw and a nyloc nut if you haven't the proper thing .

But the advantage of the spring clips as far as I am concerned is that I can fit/remove them with one hand while my other hand is hanging onto something to prevent me doing a nose-dive into the engine
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An update to you all who helped me through the elbow replacement. In the middle of a cruise to the Scillys. Bukh has been brilliant, never missed a beat. Started first time every time. Water flow not brilliant, but as witnessed here on the forum a reluctant spit with the very occasional gush.

Once almost mishap last night approaching Helford Passage after fabulous spinnaker sail all the way from Porth Cressa on St Mary's. Dropped spinnaker at the Manacle bouy, sailed close hauled into the passage. Light headwind so decided to motor up through the moorings to anchor. Furl genoa, start engine, into gear - that's funny. No throttle response, lever feels too light and easy. Into reverse, clunk, all fine. Into forward no response, though boat moving forward just under one knot. Sensing some terrible problem, lift up cockpit floor. Watch gear box lever working ok, shaft turning both ways, but no throttle. Look at throttle cable. Completely hanging loose.

Lesson: those screw and nut fittings not safe or appropriate. Should have fitted clevis pin or similar a long time ago - and the gearbox nut and screw still holding together. Imagine the problems if the gear lever had come off!

What are the spring clips you mentioned P.
 
Charlie Boy said:
AFAIk they are the same but Norris will be able to tell you. Separating the flange and elbow isn’t something you can do on the boat I found, it needs a vice etc. There is some talk earlier in the thread that the stainless weld won’t deal well with seawater, I don’t know how true that is though.
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I make bait pumps out stainless steel and the weld never rusts its solid and its in sea water all the time
 
I want to change mine back to original check this out on a bukh dv20, it gets very hot at the top.
 

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After finally getting around to fitting this elbow there is an issue that the pipe has to bend very sharp. The hose tail goes straight up in the air very close to the housing.
 
rotrax said:
With my Kiwi boat fitted with a DV 20 I installed a silencer. The main pipe from the elbow to the outlet was 50mm. It exited through a simple Vetus water trap with 50mm connectors. I deleted the water trap, put in a reducer, 50mm to 32mm to join my new silencer, ditto the outlet.

The reduced diameter gives a much more satisfying squirt out of the transom. Before at idle it was little more than a dribble.
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UMM, I hope you made sure the height limits from the waterline to the injection point to the elbow were good, preferably several meters, as vented loops are a real good idea. I forget how many engines are broken by an attempt to start them with water in a cylinder. The DV 20 does not really need a silencer, just a water trap exhaust goosneck connected to the flapper valve outlet. A keel cooled DV anything sure does, as it is a lot more local.
Found this post whilst trying to fin the dimensions of the hose that connects to the exhaust mixing elbow for a Bukh VD 24ME, I've looked in all 3 manuals, (Operators, parts and workshop), and it just aint in any of them. I need to know the ID of that hose before fitting a stainless vented loop for a newly restored engine.
 
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