On the farm I am associated with there were two tractors, a Massey Furgusson and a small older Kubota. On another farm I am also associated with they have two tractors as well, a Massey and a White. These had all been runing obn B100 for the last couple years.

This year the first farm traded in the small older Kubota for a brand spankin' new one, small but still a respectable size. This one hates B100. No sooner that the PTO is engaged and demanding a bit of torque that within 10 minutes it looses power and spews blue smoke like mad.


Apparently it is a 3 cylender, IDI engine, complete with glow plugs, but built to california emissions regs. The people at Kubota are scratching their heads and offering a full 100% refund on the tractor, but the farmer wants to push them into authorising B100 so it isn't over yet.

Anyone got any insight as to what could be the problem with the nwer Kubotas that the older ones did not have. The other ran like a chmp on B100, but the new one chokes on it.

Thanks in advance for any input.

having worked with tractors for awhile, the only thing I can think of off the top of my head is injection timing and maybe compression not being as high as the earlier models. I dont know enough about the new Kubotas to comment further than that??????

Thanks. They did a compression check on the engine and everything seems fine. I'm wondering if they didn't install some type of retarded injection to act as a type of DPF to meet Calif. emissions.

Worst case is it gets sent back to Kubota for a full refund, but it would be better to getthe trouble ironed out if possible.

Case, John Deer, New Holland and I believe also Massey Furgusson all approve B100 in their tractors, so this one is bizarre. The older one, like I said, ran flawlessly on B100 and even seemed to pick up a little "go".

They tested it with B50 and it was so-so, B20 ran better but it wasn't until B5 that it ran "normal" under load, and it did fine with PD. It's a fuel issue, but not one that has anything to do with the fuel quality, it is strickly high percentage biodiesel that it doesn't take.

Me thinks Kubota needs to arrive into the 21st century, biofuels isn't just a hippie thing anymore, it is quickly going mainstream, and Rudolph Diesel's vision of local sustainability is within reach where these farmers are concerned.

its got to be the injection timing.can the timing on the IP be bumped up easily to verify?

I have a brand new Kubota BX25 with a 23HP 3 cylinder engine that also meets the California emissions regs. The first 50 hours for the break-in I burned around B5 to B20, ever since I gave her the 50 hour service I have been burning B100 and she loves it! No black smoke, starts smoother and runs strong and steady! I have over 80 hours on her now and she is going strong. I have been working the crap out of this little machine excavating around my house so I can install new weepers. This little machine has completely amazed me and has far exceeded my expectations...

It sounds like the issue is with that particular engine and not the fuel...
You can see the exhaust manifold and muffler connection easily and there is obviously no DPF or other contraption in the exhaust on mine.
What model is the tractor?
Jon

I have a complete shop manual for mine, I just have to go and pick it up, just give me the word and I can check out how to adjust the timing or fax you the pertinent pages if your interested...
Jon

have you tried adding power service additive to bump up the ctane? But it does sound like a timing issue one of my drivers in a 2007 int 4300 says he can tell a noticeable diff when I add power service esp when he has a 10k truck on the bed. I generally use PS every 3rd tank for preventative measure

I assume you've siphoned the tank and put mostly Diesel back in, and tried it out.

I'm dealing with some smoke issues with my 81 VW. I just bought it and went to B100 (and haven't gone back to 100% petro-diesel, so I am still learning. However, here are some of my thoughts.

• Just discovered someone had removed the manual throttle limiter, thus it was running richer than it should have been on full throttle.
  
• In general, a simple non-turbo Diesel Engine will have troubles maintaining a stoichiometric fuel/air mix at full throttle. Tendency to run rich.
  
• A broken or malfunctioning Turbo might cause smoking as well as lack of power.
  
• What is the engine temperature. If I'm driving "feather footed" to avoid smoking, It can be several miles into the trip before I get to "normal" temperature.

Anyway, so my thoughts would be:

• Make sure it runs fine with Diesel. Don't want to bark up the wrong tree.
  
• Make sure turbo and "standard equipment" are intact.
  
• Check thermostat and engine temperature. Perhaps bump it up slightly. Also, make sure you have good antifreeze.
  
• Consider forcing intake to come over exhaust manifold.
  
• Consider fuel preheat system like with SVO/WVO

there's an ides check the thermostat and make sure it inst stuck partially open engine not coming up to temperature. A rich fuel condition (you only notice this smoking condition during full throttle under a load) could be quenching the combustion chamber temperature might be just enough difference in the Btu's of bio diesel and petroleum think it averages somewhere between 7-10% less for bio diesel

To make my diagnostic logic happy, you need to run the same fuel in a known "B-100 happy" tractor to confirm that this isn't a freak bad batch of biodiesel. You've probably done that already, but if not, it wants doing.

Finest regards,

troy

Ok, it is a KUBOTA B 2920 HSD....series #53237 3 cylinder IDI (or so we're told - got glow plugs though).
The same fuel that has been in the Massey and that has run inthe older Kubota is what went into this one. There are 2 other tractors runing on it too, a White and another Massey. It ain't the fuel.

It was emptied and then tried on dino and ran well. Then B5 was tried and it ran well. B50 and it went to crap again, just like B100. I'd say it was the fuel if it wasn't doing fine in everything else (2 cars and 3 tractors) without smoking or losing power.

Thanks for those who came back. It's a brand new unit, less than 25hours on it, so mcking with it is best left to the dealer who seems to be nice about it all and will refund 100% of the unit price if that is what the farmer wants to do, but we shall see.

Any other ideas ? I'm all ears at this point.

Quick look through kubota site. The BX25 doesn't have, the B2920 does have "E-TVCS" three vortex combustion system.

Does Kubota allow running B100?

quote:

Originally posted by Paulus:
Quick look through kubota site. The BX25 doesn't have, the B2920 does have "E-TVCS" three vortex combustion system.

Aha! Thats the problem it has the new fangled E-TVCS system which is short for the "NFG system"!
Gotta love technology eh!
Good find Paul!
I picked up my shop manual today and went over the complete intake, fuel and exhaust system and there does not appear to be any type of emissions widgets on my machine anywhere... Thank goodness!
Please let us know how this all works out for your buddy Legal.
Jon

quote:

Originally posted by Raften:
Does Kubota allow running B100?

Nope, only B5...
Bunch of deadbeats!
Jon

oh jeeze.....

is it possible that the engine needs to be broken in first?
have the 2620...but only 2 hours on it right now, plan to run reg diesel for the first 50 then onto b100.

my older kx121 excavator runs just fine on b100

I doubt it Phred, the break in period is more about steel mating surfaces and not about combustion of the fuel.
It doesn't sound good to me...
Here is some more information about the NFG system HERE.
Actually I cant see how the better combustion chamber in that system would have a negative impact on burning biodiesel so perhaps something else is causing the grief...
In any event I hope the dealers make things right for those involved!
Jon

For all appearances it looks like this one is for the dealer to play with. Perhaps an ajustment to fuel/air might do it. Would it be that under load the fuel is too rich and thense the blue smoke and loss of power ? They must have used the same techies that Mercedss have ... you know, the ones paid by Big Oil to design out biodiesel ?