Bukh DV20 Engine issue and Questions

[Alistairr]

Hi all,
Hope everyone is keeping safe and well during these unprecedented times?

We have had a Moody 29 for 3yrs now and are enjoying learning to sail her but have done very little to it other than regular engine maintenance.

Last year we had a few engine failures, each time the engine would start fine to leave the mooring, but try to restart after sailing, it wouldn’t restart, I had to bleed the fuel each time to get it restarted.
Our engineer spent sometime on the boat and couldn’t see a cause, apart from a chip out the glass bowl of the fuel filter, we replaced that but still didn’t solve the occasion problem.

We are sure there is air getting into the system somewhere, but we have checked everything and can’t see where.
Anyone got ideas of what to check if the issue arises again this year.
I did change from red to white diesel, but surely that wouldn’t make any difference.

Also I’ve read that the Bukh DV20 engine tend to steam out the exhaust as the water pump is on the small size and ours does do this, I read on here a larger pump is available, does anyone know if these are a straight swap and have a link to where I can get one?

Is there any other issues I should look out for with these engines?

Many thanks,
Alistairr.

 

[europe172]

Hi all,
Hope everyone is keeping safe and well during these unprecedented times?

We have had a Moody 29 for 3yrs now and are enjoying learning to sail her but have done very little to it other than regular engine maintenance.

Last year we had a few engine failures, each time the engine would start fine to leave the mooring, but try to restart after sailing, it wouldn’t restart, I had to bleed the fuel each time to get it restarted.
Our engineer spent sometime on the boat and couldn’t see a cause, apart from a chip out the glass bowl of the fuel filter, we replaced that but still didn’t solve the occasion problem.

We are sure there is air getting into the system somewhere, but we have checked everything and can’t see where.
Anyone got ideas of what to check if the issue arises again this year.
I did change from red to white diesel, but surely that wouldn’t make any difference.

Also I’ve read that the Bukh DV20 engine tend to steam out the exhaust as the water pump is on the small size and ours does do this, I read on here a larger pump is available, does anyone know if these are a straight swap and have a link to where I can get one?

Is there any other issues I should look out for with these engines?

Many thanks,
Alistairr.

Re steaming out the exhaust
My experience, the Bukh works differently to many engines, the cooling water bypasses the engine until the thermostat opens, cold water enters the engine and hot water is dumped into the exhaust . This can cause a on off steaming effect. That said the engine is also sensitive to the thermostat housing reducing the effectiveness of the thermostat and scaling in the block can cause local hot spots. Increased water may not reduce steaming. Check you have the correct thermostat, check the housing is clean and use a spot thermometer to measure the block temperatures

 

[vyv_cox]

On the hot restart problem, it might be air but I have difficulty in imagining why high temperature would affect it. I suggest you look at tappet clearances, they are quite tight anyway and will reduce with temperature.
Coolant flow is low on the Bukh, the seacock is only 1/2 inch., so there is always a tendency for it to be hot. All raw-water cooled engines tend to foul with carbonate salts, easily fixed with Rydlyme treatment.

 

[Poignard]

If bleeding the fuel system enables it to be re-started then that must be where the problem lies.

You refer to "our engineer" but if this is a problem he cannot cure then maybe it's time to employ another (as you would a doctor).

 

[Charlie Boy]

I had this problem some years ago. Nipping up the joints wasn’t enough. In the end I replaced most of the with Dowty seals, much more effective but not quite as durable as copper washers. Still, they cost peanuts and it’s a matter of moments to replace them.
http://www.potterassoc.com/pdf/bonded_seal_information_and_sizing_chart.pdf

 

[Poignard]

I had this problem some years ago. Nipping up the joints wasn’t enough. In the end I replaced most of the with Dowty seals, much more effective but not quite as durable as copper washers. Still, they cost peanuts and it’s a matter of moments to replace them.
http://www.potterassoc.com/pdf/bonded_seal_information_and_sizing_chart.pdf

Useful to know. Thanks.

I suppose you can buy small quantities on eBay?

 

[colind3782]

Might be obvious but is there plenty of fuel in the tank? I had a similar problem a few years ago when I was down to about a 1/4 tank and running across a bit of chop which caused the fuel pipe to draw in air.

 

[Charlie Boy]

Useful to know. Thanks.

I suppose you can buy small quantities on eBay?

Yes, although i got mine from a hydraulics company, Pirtek.

 

[neil_s]

The larger capacity pump has four screws to secure the top plate while the smaller capacity one has six screws. Counter intuitive - I know! I still have the smaller one in the spares box. It is a direct swap. The larger capacity pump is a Johnson F35.

 

[Poignard]

Johnson Flexible Impeller Pump 10-35157-3

 

[Charlie Boy]

Johnson Flexible Impeller Pump 10-35157-3

used to be able to get a refurb kit for those but I haven’t been able to track them down.

 

[Hostage]

Re the fuel problem.
The original lift pump on the Bukh had a small internal filter about 8 mm in diameter. They were prone to collect dirt from the fuel and starve the engine.
I had this problem. The engine would run for a while but was slowly starved and the filter bowl became empty or low. Priming replenished the bowl and the engine started again and if running at low revs may well keep going for a while. Fickle!! Well known problem. Bukh UK usually advised that it be removed although I just kept it in place and added it to the service list.

 

[Dave.S]

Hi all,
Hope everyone is keeping safe and well during these unprecedented times?

We have had a Moody 29 for 3yrs now and are enjoying learning to sail her but have done very little to it other than regular engine maintenance.

Last year we had a few engine failures, each time the engine would start fine to leave the mooring, but try to restart after sailing, it wouldn’t restart, I had to bleed the fuel each time to get it restarted.
Our engineer spent sometime on the boat and couldn’t see a cause, apart from a chip out the glass bowl of the fuel filter, we replaced that but still didn’t solve the occasion problem.

We are sure there is air getting into the system somewhere, but we have checked everything and can’t see where.
Anyone got ideas of what to check if the issue arises again this year.
I did change from red to white diesel, but surely that wouldn’t make any difference.

Also I’ve read that the Bukh DV20 engine tend to steam out the exhaust as the water pump is on the small size and ours does do this, I read on here a larger pump is available, does anyone know if these are a straight swap and have a link to where I can get one?

Is there any other issues I should look out for with these engines?

Many thanks,
Alistairr.

Hi Alistair,
I have a hunch I may be able to help with the engine not re-starting. I too have a Moody 29 & DV 20

Hi all,
Hope everyone is keeping safe and well during these unprecedented times?

We have had a Moody 29 for 3yrs now and are enjoying learning to sail her but have done very little to it other than regular engine maintenance.

Last year we had a few engine failures, each time the engine would start fine to leave the mooring, but try to restart after sailing, it wouldn’t restart, I had to bleed the fuel each time to get it restarted.
Our engineer spent sometime on the boat and couldn’t see a cause, apart from a chip out the glass bowl of the fuel filter, we replaced that but still didn’t solve the occasion problem.

We are sure there is air getting into the system somewhere, but we have checked everything and can’t see where.
Anyone got ideas of what to check if the issue arises again this year.
I did change from red to white diesel, but surely that wouldn’t make any difference.

Also I’ve read that the Bukh DV20 engine tend to steam out the exhaust as the water pump is on the small size and ours does do this, I read on here a larger pump is available, does anyone know if these are a straight swap and have a link to where I can get one?

Is there any other issues I should look out for with these engines?

Many thanks,
Alistairr.

Hi Alistair,
I have a Moody 29 with a DV20 also, I had a similar possibly the same issue of restarting after warm/hot. If you care to email me I am happy to explain and send pictures
Kind Regards
Dave
dave.skinner@live.co.uk

 

[TNLI]

Anyone know which anti freeze or coolant BUKH recommend for a DV 24 ?? I've looked at the various manuals but can't find the requred spec.

 

[Rhylsailer99]

i replaced my fuel assembly with a new delphi unit and have had no problems since as i had a similar problem. My boat had a copper tube plumbing type system but i bypassed all that with a rubber hose .

 

[RichardS]

Anyone know which anti freeze or coolant BUKH recommend for a DV 24 ?? I've looked at the various manuals but can't find the requred spec.

As this old thread is about a raw-water cooled engine, you might be better off starting a new thread.

If the manual is not specific, I would use a cheap long-life/OAT antifreeze for your engine. I buy 5 litres concentrated pink/orange OAT for £12 at my local automotive trade supplier.

Richard