Bukh 20 DV engine: Starting/Restarting fuel problems after running out of fuel yester

[nuku34]

Captain Caliamari:
Greetings from New Zealand.
I have a Bukh DV20 in my 10m sloop. I’m very knowledgeable about this engine and about marine engine systems in general having spent 17 years full-time cruising on 3 different yachts.
1) Yes, the Bukh, unlike many other “marine” diesels, is a true marine engine from the ground up, NOT a marinized tractor engine. The smaller Bukhs were designed for use in lifeboats and something like 90% of commercial lifeboats have them.
2) I won’t comment on your fuel blockage problem as it seems you have that sorted. Do use a fuel biocide or you will get the dreaded diesel “bug.”
3) Re Glass or plastic bowl vs metal bowls on first stage filter/water separator units like the Raycor: Glass or plastic bowls are prohibited and metal mandated for use in enclosed spaces only if you have a petrol engine. If the glass breaks and you get petrol (gasoline) in your engine space you are looking at a potential explosion! Not so with diesel.
4) Get rid of that **-king Raycor. The replaceable Raycor brand filters are way too expensive, and the bowls are not glass, but plastic, and prone to cracking. Get a filter/water separator unit from an auto supply place; Delphi is a good brand. The filters are ⅕ the cost of Raycor and are just as effective. The Delphi units actually do have a real glass bowl, very thick glass and it will never crack.
5) Why not just MOVE the bloody filter out from under the sink area? It can be anywhere that is easy to get to and should be easily accessible. You might have to replace the rubber hoses that go from your fuel tank to the filter and filter to fuel pump if they’re not long enough. No big deal.
6) Oil leaking out of the engine:
A) If its leaking out of the front of the engine, from behind the big flywheel, it is probably coming from the crankshaft seal. If the seal is in bad shape, it can be replaced. The workshop manual will explain how this is done. If you are not handy with tools and machinery, get a mechanic to do it (doesn’t have to be an expensive “marine” mechanic, Its just a diesel engine for god’s sake).
Ather possibility is this:
For reasons I won’t go into here, the Bukh DV20, by design, creates a positive pressure in the crankcase. This pressure is normally relieved by a small one-way valve under the valve cover. If this valve gets clogged, the positive pressure in the crankcase will force oil out of the cankshaft seal. Take the valve cover off (2 big nuts on top), remove the one-way valve (its a metal tube/like thing) and blow into it to make sure its working. If not, submerge it in petrol for a while and blast it with compressed air. While you have the valve cover off, you should adjust the valve clearances. The manual says to do with every 150 hours.
B) Your water pump may have a leaky seal on the engine side of the pump. This is obvious if you just put your finger under the pump where it connects to the engine. if your finger has got oil on it, there’s an oil leak. Take off the pump, tear it down and replace the seal. NO big deal if you are at all handy with tools and machinery.
6) The DV20 is normally a raw salt water cooled unit. Very few were built with a heat exchanger or with keel cooling. If yours is a salt water cooled engine, you need to flush it out with acid at least once a year, AND replace the zinc anode in the block. Failure to do this will eventually cause the engine water passages to fill up with salt and corrosion and the engine will overheat. If it over-heats badly, you are in BIG trouble.
7) The DV20 is a great little engine, very robust. If properly maintained they will last for many years and 1000’s of hours. if you are planning on extended trips away from civilization, you really do need to learn how to maintain that engine on your own and carry the necessary spares.
Good luck,
Nuku

[johnn33]

Bukh have been part of Proteum in the SC Group for some years
https://scgroup-global.com/group-companies/proteum/
They do good work for the R N L I in the UK
John