Bukh DV20 madness!

[unclebraddah]

Here is a letter I just sent to Bukh. Any thoughts?

Hello. I have a Bukh DV20 built in 1973. I am sorry I dont have engine # but I hope they are fairly standard. My engine starts, and just before reaching normal RPM's dies. It will keep puttering if I keep the starter going.
It happenened all of a sudden. I needed to put a new valve cover gasket on because it was leaking oil. A minor maintenance issue. Of course I thought air in the fuel so I put a clear return line off the filter bowl back to the tank. yes there is air.
I have cleaned the lift pump and removed that little filter, It seems to be pumping fine.
I have replaced the Filter Bowl filter and seal and even tried running it without it. No change.
I have resealed Banjo fittings.
I have completly taken apart and put back together the Injector pump.
I replaced the high pressure lines from Injector pump to injector.
I have cleaned and inspected and retorqued injectors.
I loosened the rear High Pressure(HP) line and it kept running(with starter help)
I loosened the front HP line and it stopped.
I switched injectors and it remains that if the front HP line is loosened the engine stops dead.
I hooked up an electric fuel pump directly to the filter bowl from a supply above the bowl.
I Checked the Manual Govenor Spring wire to make sure it was caught in it's proper holes. It is but there is no response or acceleration if the shaft is turned, yet there is a return.

So...today I will check the Valve vacum system above the vales and am getting ready to tackle inspecting the centrifugal govenor.
But I feel it is something simpler having to do with me changing the valve cover gasket. Did I not adjust the compression lever proper? If so did I do valve damage? Everything looks OK. I have compression.

I really like this engine but it has been down since April. Im getting so frustrated I am looking at other engines infourtuantly. All the forums say to call you guys. It is a 12 hour time difference as I am in Hawai'i. So it is difficult and I want to make sure I have the right answers to any questions you might have.
/forums/images/graemlins/laugh.gif

 

[Peterduck]

Have you looked at the fuel line back at the tank outlet? Many fuel tanks have their delivery line exiting through the top of the tank, so that the fuel has to be sucked out, rather than just flowing out under gravity. If there is a small hair-line crack in the fuel line, it will admit air and you will lose your suction. From what I have read in various sailing mags, this is not a rare ocurrence.
Peter.

 

[EASLOOP]

Are you certain that the decompression lever is not holding an exhaust valve partly open. My experience is with my 1973 DV10. I presume the 20's have a decompression lever?

Hang in there. Bukh are argualbly the best marine engines around.
good luck

 

[unclebraddah]

Yes they do have the decompression lever. I am having the dickens of a time getting it right I guess. There are three points within the decompression piston right? Forward(which is up and running) The next stop is adjustment which is just touching the exhaust valve and the lever perpendicular to the engine.(How you are supposed to know when it is just touching considering the valve cover needs to be on when doing this is and you have spring tension on the decompression piston is frustrating.) and third stop all trhe way back is the decompression point pressing on the exhaust valve allowing for easy engine turning. I put a thicker gasket on the valve cover (which is when this all started) but wouldnt that free up the valve even more? So today I am going to try it with a smaller gasket and I will let you know what happens. Thanks alot. I like this Bukh as well and it's(seemingly) Heavy duty simplicity.