Hi every one I’m a long time reader and have got lots of great information for your forum
My boat is a compass H28 from N.Z. lots has been done since I bought it almost a year ago and I’m basically doing a full refit.
I thought I’d share my experience of replacing my old bukh 20hp with a modern Beta 20 based on a Kubota d722.
The beta engine I found on gumtree it sounded too good to be true a 2008 model brand new never installed at a bargain price locally so I jumped on it that day .only 2 weeks before I was speaking to beta and nanni about prices for a new engine and it looked like I had a lot of saving to do.
The beta did need a new alternator/ starter motor an impeller new oil line filters/oils and a fresh coat of paint. I also found the thermostat to be stuck closed and replaced it.
So what was wrong with the bukh well it leaked oil everywhere it was always hard to start especially when cold and needed 2 fully charged battery’s to turn it over.
Most bukhs don’t have glow plugs they have manifold heaters which is essentially a small diesel fire in your manifold/air filter that the engine sucks when cranking I didn’t like the idea of that at all check this you tube clip out
Bukhs don't have manifold heaters you can buy one but Ive never seen one in Oz fitted
In my walker I got 6 to 6.5 knots out of my dv20 . I wonder if you were getting full throttle on the dcv20 = 20 hp in a Bukh is calibrated differently than other marine motors
My bukh is over 37 years old will your beta last that long? 
Do you think your Beta will last that long with out leaking oil?
What I didn't like about my old bukh was its operating temp 42 c its to low not good for any diesel engine to run that low
If your down in Mexicanville any time Ill give you a race around the buoys 
and a few drinks after 
Im putting in this bad boy an oldie but a goodie DV 24 putting my dv20 out to pasture
Cheers Kurt she look great
Cisco will be in here in a minute he loves Betas
Looking forward to your posts
Thats a nice prop shaft coupling Kurt
Kurt just wondered if you have check two things
1 . When you give the throttle handle full throttle in the cockpit have you checked where the throttle is at the injector pump
2 . have you calibrated the tacho on either of these motor 1500 rpm and 2000 dont seem right
hi thanks for your comments
went down to the boat today far to hot to do any work but had a swim and took a few more pics
yes my bukh was old about 37yrs I think (boat was built about 1977) it was tired had problems and needed repairs. i'm shore a brand new or rebuilt bukh would be more comparable but still heavier and less refined.
bukhs are stronger there is no debating that and they may last longer if installed right and maintained but this is represented by the extra weight.
the biggest killer of any marine diesel is water syphoning back through exhaust this cannot happen with the exhaust I have designed.
5knot was flat out with bukh i expected more .I had a bw7 transmission that might have a different reduction to yours
I was considering rebuilding the bukh my self but found the bukh repair manual to be eligible at best and parts expensive and hard to come by.
The beta is a marinised Japanese Kubota d722 which are found in tractors , mowers any many other applications and is also used by nanni for the 21hp
I worked as a mechanic when I was younger and know kubotas very well they are super reliable and should last for 10,000 hrs or longer and I hope by then I have a bigger boat .
kubotas are also very easy to work on with detailed repair manuals and cheep available parts.
if anything happened I would simple rebuild it myself for about little over $1000 or I could buy a rebuilt Kubota exchange of ebay for $2400 with warranty.
I have rebuilt many car engines when I was working as mechanic and you don't change every part and cant a new engine will always run better and last longer than a rebuilt one. plus I now know my engine and system`s very well now . the whole job was completed for less than a bukh rebuild and everything is new.
bukhs you either love them or hate them. I do respect what they are "a true marine engine" and how strong they are built . but the beta in my opinion is a better choice for me and the fact it runs so smoothly and weighs less is a huge plus for my little boat.
the boat sits at least 2 inches higher on the waterline . and the bulk of the engine Weight is lower than the bukh
my bukh used to operate between 50 and 55*c maybe there is a different thermostat you could use
bukh do sell the parts to convert it to closed cooling system to raise the temp right up I believe lots of dv24 are closed cooling from factory
yes my bukh did have a manifold heater I have seen a few others fitted too they are not standard but bukh do sell a kit to retro fit
the beta is getting full throttle it will rev all the way past 3000rpm in neutral
I did confirm the taco is correct via a digital tiny tach tacho and the throttle is adjusted correctly
your boat is very nice hg I have been following your build, you are finishing it to a very high standard. i don't think il be heading south in a hurry but maybe one day well cross paths my boat kept in the broken bay area
I've watched that n.z clip about a 100 times great looking boat on the inside.
the Volvo seal is great very simple and cheap to buy no more drips no more smelly grease and adjustments .i do have to give it a small amount of Volvo grease every 100hrs or so
the water injection made a huge difference to the temps with it off it would get a little to warm for my liking
I still have a few small things to tidy up and cant wait to get my prop sorted I will let everyone no the results
Kurt
You done a nice job on her Kurt .
I know what your saying between the two reds one was grown on the north ridge the other on the south power to weight ratio does count no matter what your building and altering and its choices . thank god we are all individuals.
My boat is not nice it has untold unfinished projects Kurt 
and I seem to make the list get even bigger some times but my choice of the dv24 was a cheap up grade the dv20 I feel needs a minor rebuild and the dv24 was going to get one now but as it started in 3/4 of a revolution after sitting stationery for over 9 months I thought the money can be used else where and if it need attention later Ill do it .
To me the DV24 is a refinement from the older dv20 easier start smoother running and higher operating temp both my thermostats open at the correct temp range. The only other thing than fit a new water pump to the DV24 was clean out the years of crud inside the motors cooling system . As I work with caterpillar if I was replacing Id buy a cat engine. but the dv24 was a cheap alternative
Kakahi Ive watch many times its inspiring when you need some inspiration
Your prop seems its been a bad choice when first fitted years ago.
I do like your instrument panel I looked around every where for one could find one. I ended up making my own which is still unfinished perhaps its because the boat knew some thing else was needed first
Keep posting I enjoy your work
thanks hg I think your boat is coming along nicely I have seen some of the work you have done to it like the bowsprit windows kitchen kero oven interior engine room ect
your engine gauge panel inspired me to make mine so thanks .
boats in general brand new or 50years old are unfinished projects there is always something to ad fix or improve on when your done you will have a excellent boat much nicer than those tacky French/German boats
the dv24 will be a good improvement its was the dv20`s successor it sound like it starts easy too just drop her in .no point rebuilding if there are no know issues just check for any oil leaks and oil pressure and you good to go
Select to expand quoteh28kurt said..
thanks hg I think your boat is coming along nicely I have seen some of the work you have done to it like the bowsprit windows kitchen kero oven interior engine room ect
your engine gauge panel inspired me to make mine so thanks .
boats in general brand new or 50years old are unfinished projects there is always something to ad fix or improve on when your done you will have a excellent boat much nicer than those tacky French/German boats
the dv24 will be a good improvement its was the dv20`s successor it sound like it starts easy too just drop her in .no point rebuilding if there are no know issues just check for any oil leaks and oil pressure and you good to go
Cheers Kurt
Ill order new engine mounts and a engine / gear box coupling rubber and next year start collecting a few rebuilding parts before the Government put the cost up with there charges in a couple of years
Select to expand quotecisco said..
I am not going to say anything except you are both doing a great job.
yer right Cisco
I had the 3 cylinder Kubota as an auxillary and it was fairly faultless for 17,000 hours. Lot depends on who does the conversion. Only real failures were fresh water water pump and it chewed of belts regularly.
