Biodiesel

California

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Report #5

I think I've tamed the beast.

I added Power Service (silver bottle, cetane improver but no anti-gel) at their recommended half-strength, 3.2 oz per 10 gallons for a 3 Cetane point improvement. (Their recommended maximum is double that, ie 3.2 oz in 5 gallons to give 6 Cetane points.) Since biodiesel improves Cetane I didn't think I needed the maximum. I didn't add any petro diesel so I'm running straight B100.

This now starts acceptably. The weather is warmer and my mid-morning starts have been around 55 degrees. With Power Service in the fuel it starts in under 10 seconds cranking and with far less smoke.

For the curious, here's a vid.
BioD2Start. 1 minute, 2 mb.
First start after a week parked. It fires at the seven second point of cranking although subjectively it feels longer.

I had mentioned slow re-starts on pure B100. With the PS added it is back to firing right off like it always did.
Biod2ReStart. 28 sec 1 mb.
This is only moments after the first start of the day but it starts instantly. Includes a few seconds of driving off into the orchard.

Just for fun if you're still with me - My wife taped some actual work. I am using the backhoe to transplant a tiny tree.
DigTinyTree2. 3 minutes 6mb.
As this vid starts I am carefully getting disintangled from another tree I had to park too close to. Then I finish digging out the tiny tree at right angles from my first cut. (I trench around a tree to be moved using a # pattern.)
This thing clatters even when it isn't breathing hard!

Summary: Power Service at 3-Cetane-point concentration level brought the B100 into the range of acceptable starting. Once started, it runs the same as petro diesel. I don't notice any soot and come to think of it, I didn't notice any exhaust smell either.
 

PBinWA

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It would be interesting to see what happened if you switched back to standard diesel. I kind of wonder if the B100 just cleaned out your system and the benefits you are seeing are from the cleaning or if it really is the B100.
 

California

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It would be interesting to see what happened if you switched back to standard diesel. I kind of wonder if the B100 just cleaned out your system and the benefits you are seeing are from the cleaning or if it really is the B100.
I don't think I'm seeing any direct operating benefit beyond less toxic exhaust. I assume that returning to petro diesel would go back to the same unpleasant exhaust as before.

My application presently consists of standing still doing backhoe work, where I can't escape the exhaust cloud. Examples of current projects: Aside from that tree transplant pictured in my previous post, I'm mostly pulling 'weeds', ie blackberry and scrub oak roots that are sometimes bigger than those of the orchard tree that they have choked. Here are a couple of pictures I posted in another thread showing how I snag a weed then pop it out like a carrot:

Technique

Root

Now using the same proportion of Power Service that I use in petro diesel, it still isn't quite as easy to start. I think the Flash Point of biodiesel is higher than petro diesel.
 

California

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90 day followup:

I got tired of the reluctant starting so I blended in petrodiesel as I used up the first tank of fuel. It was running about B85 by the time that first tank was empty. Starting was improved, but not excellent.

Then I discovered that one of the slow starting issues is an undersize starter. The starter that belongs on this Yanmar is 1.8 kilowatt and direct drive, while the actual replacement starter on it is a gear reduction 1.2 kilowatt unit, maybe off a garden tractor or something. Just one more thing I've found where the previous owner threw parts at it without regard for Yanmar specs. I thought I had found and corrected all his errors but this is one more. (The correct starter costs $215 for a rebuilt. I can see why he went with a smaller one.)

I'm running B92 ? (1:11, 0.5 gallons petrodiesel + 5 gallons biodiesel). Starting still takes about five seconds of cranking with white smoke, unburned vapor, before it fires off. Maybe faster cranking would fire easier.

Warm starting is fine, but it still takes an instant longer than it did on petrodiesel.

Power is fine. Mowing is the heaviest task and I don't see any difference.

Exhaust smell is far better. It doesn't smell like doughnuts, however. There is occasionally a slight smell, that is much more obvious in the raw fuel. It smells like cheap meat-based dogfood, sort of a soured grease smell. My source is a refinery that processes Reno casino and restaurant kitchen grease, and I suspect this fuel still has the smell of its origins. Forget doughnuts.

I've also noticed when refueling that the viscosity of the fuel is noticeably thicker than petrodiesel. Christenson's article referenced above shows much higher viscosity for vegetable-based biodiesel. I wonder if there is some of that in this fuel.

In summary: It works.
 

oldgrayfellow

New member
Biodiesel in YM-186D

After California's intrepid example with his 240, i wanted to run biodiesel in a 186D, and needed to find out whether there were any rubber or other parts vulnerable to BD in the 186's fuel system.

According to Aaron at Hoye tractor, it seems there's just one o-ring near the outside of the injection pump, and one each on the fuel valve and filter bowl.
So as California found for his 240, there doesn't seem to be much rubber to worry about in the 186 either. Here's a link to the thread:

http://www.yanmarowners.com/phpbb/viewtopic.php?f=1&t=1102

Many of the tractor manufacturers seem reluctant to officially sanction use of B100. Likely they're mostly interested in avoiding liability, since they have little to gain by approving it.. but it doesn't seem likely to me that using properly made B100 should give any problems other than the effects on starting etc. that California mentioned.
 

California

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Update February 2010. I'm still working from the same 20 gallon batch of B100. This was mostly backhoe work with typical fuel consumption well under 1/2 gallon per tach hour. And a tach hour is nearly 2 seat hours because just over half the 'pto' rpm is sufficient for full backhoe hydraulic pressure. Plus I have tried various proportions, B80, B50, etc so this first purchase went a long way.

In the dead of winter at 100% humidity, 45 degrees, when any warmth causes cold metal to sweat, I had to use the hair dryer to push warm air into the intake to ease starting. Then I decided to just use the hair dryer on low for a half hour to warm the side of the cylinder head to about 85* which works great.

Finally I diluted the B90 down to B50 since it would be a real mess if I ever had to leave the tractor out stuck in the mud then make a cold start without 110v available.

In summary B90 starts ok down to about 52 degrees and moderate humidity. But 100% humidity and cold, like what fogs your car interior while its foggy drizzle outside, really makes this stuff hard to start.

I have B50 in the YM186D and that starts within a second or two of cranking, much easier than the YM240 which is a big twin, much harder to crank over.

Also, new biodiesel users are warned that the stuff is a good solvent and will loosen all the crud in your fuel system. But I haven't seen any filter blockage in the YM240 over a year's time. It started out pretty clean; I cleaned it thoroughly in 2003 when I bought the tractor with bad fuel in it.

One tip: I got some Litmus strips off Ebay to test my biodiesel since I have had this batch a year now. (mine tested fine). In one article I read on early biodiesel experiments, a municipal diesel electric generating plant was badly damaged by highly corrosive biodiesel, the consequence of bacterial action as old fuel aged. It was way out of spec and the experimenters didn't notice until the engine soon quit, with expensive damage. So old fuel acidity is a factor to keep an eye on if you store it beyond the producer-recommended shelf life of six months. (their recommended shelf life for petro diesel is one year). My source said he has stored biodiesel fuel beyond two years with no noticeable difference. I recommend test for acidity occasionally with the Litmus strips if you still have biodiesel beyond six months of purchase.

Onward!

Oldgrayfellow, thanks for the good word! Since those rubber o-rings only secure the outlet connectors to the fuel pump, any sign of leakage would begin as easily seen sweating on the exterior of the pump. Likewise, the o-rings at the fuel filter. I think this sweating would give you plenty of warning to replace the (inexpensive) o-rings before any harm is done or the tractor becomes hard to start. So I don't think those o-rings are an obstacle to trying biodiesel.
 

California

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The experiment is over.

Back to the drawing board.

I noted it was hard to start in February @ 100% humidity and temperature in the 40's. As spring progressed and the weather got warmer, the starting continued to get more difficult. I drained the biodiesel and ran straight petro diesel for one tank; no improvement. I concluded I had crudded up the injectors.

The Operation Manual says clean and test the injectors at 600 hour intervals. I asked a local injector shop about this and the first thing he asked was 'has it had biodiesel in it?' He said part of running biodiesel is more frequent injector cleaning since the heat inside the nozzle cooks grease to hard deposits like on a pancake griddle. And there are big differences in the quality of biodiesel available. He said for some reason intermittent operation is worse, a tractor used infrequently and not run hard is the most subject to problems.

He said he has to soak injectors in a bucket of carburetor cleaner for a couple of days before he can disassemble them. And in my case the injectors hadn't been out in literally decades so they were likely to have wear or corrosion making them unrepairable. His price to overhaul each injector was $30 labor minimum plus new nozzles which might be $60-80 and he wouldn't quote a total price before working on them.

I bought two new injectors, $107 each. (I'm glad it's a two cylinder engine!) While injectors serviced periodically should be easy to pop in and out, these were cemented in hard. Each injector is about an inch diameter and slides down into a bore 1.5 inches deep before reaching the gasket surface. I devised a puller and found these were a heavy push fit all the way out. After cleaning the bores, the new injectors slid right in and should come out easy next time.

What have I learned from this experiment? First, the recommended 600 hour cleaning can be neglected for years on clean petro diesel and the thing will still run. Not so on biodiesel, the injectors will need cleaning at regular intervals. For this 'Old School' tractor the cleaning instructions are included in the manual: disassemble, clean, and polish the nozzle orifice using "only a wooden stick and mutton fat." !!!!!!! (I think I would start with a soak in carb cleaner.) The only cost if you do it yourself is $3 'insulators' (teflon gaskets) that seal the tip of the injector to the head.

I'm not going to experiment further; my use always will be intermittent and low-load. I'm going back to petro diesel. The YM240 (twin) now starts easily and runs like new again. The little YM186D ran fine on biodiesel but I don't want to repeat the problem on that one so it now also has a diet of petro diesel.

Ok, what should I experiment with next? :)
 

Doc

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Good experiment and follow up report Chris. :thumb:
Let me think on it as to what you should experiment with next. I might be able to come up with something good. :D
 

WFH

New member
I am not sure how many of you live in cold climates but I have found if you live in area's that get below freezing running bio diesel can be a bit of a pain. I used to work for a large construction company here in the north east and they once tested using bio diesel. The first part of the year not much of a difference was noticed. Just before the fall of the year some machines started smoking a little heavier and there was a slight increase in fuel consumption. The colder it got going into fall the harder the machines started, and the more they smoked on start up, warm up, and under heavy load. When winter hit with freezing temps The real trouble began. We had major problems with gelling and separation. Even with cutting the fuel with K-1 and using diesel treater we continued to have problems though it did help dramatically. Long story short. I would guess that if you live in warmer climates or during summer use it could be O.K. to use, But from what I have experienced cold weather is no friend to bio diesel.
 
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