B7000 won't start after running dry

5thhorseman

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B7000, Allied 95 FEL, Sovema Tiller, Blade, on 3 overgrown acres
Oct 21, 2010
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Aldergrove, BC
Hey all! I'll start this off by saying that I am not mechanically knowledgeable, on either gas or diesel engines, but am willing to learn.

I have a v. old B7000 that has run fine for the last 4 years. The other day I ran out of gas. No big deal I thought, as it's happened before. I filled up the tank and bled the injectors and started her up. However she wasn't running the same anymore. I had to put her in Low to get up a moderate incline, and when I put her in neutral it took a long time to get back up to normal rpm I'd expect. It was as if only one cylinder was firing.

So I figured that the fuel I put in must have been bad. I don't use the tractor too much and it could have been up to 6 months old. So I drained the tank, replaced the fuel filter while I was at it, put in fresh fuel, and bled the lines again, this time both at the pump and at the injectors. I can see fuel sputtering out as the engine turns over.

But she doesn't start at all now. Just seems to turn over and not really fire or get close to starting. Smoke is coming out (so there's fuel being delivered, I guess) and it's a dirty white colour.

Battery is new as of last year but I was guessing it was weak. So I put it on a trickle charger for a few days. Today I put it back in and also ran jumpers from my car for some extra juice. Same result. It's around freezing right now and the tractor is outside (not under cover) at the moment.

Wondering if I should consider the battery angle a bit further (maybe go out and buy a proper charger/tester) or look at the glow plugs.

I'd appreciate any help I can get. Thoughts anyone?
 

D2Cat

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Probably fuel and battery are fine. Glow plugs is what I would focus on. Do you know if they work, use to work, or never worked?

On my old L305 I have to turn on the keys switch one click clockwise. Then turn the main switch counterclockwise to get power to GP. When you go through the process on your tractor does the glow plug indicator light up?
 

5thhorseman

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B7000, Allied 95 FEL, Sovema Tiller, Blade, on 3 overgrown acres
Oct 21, 2010
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Aldergrove, BC
Hi, thanks for the reply!

Glow plugs have worked in the past. The indicator light does go on but I'm not sure if it can light up if one or more glow plugs has failed. Are the glow plugs in parallel circuits but in series with the indicator? I don't know.

Thinking about the last few years I recall now that starting has slowly got worse and lately it's been just barely starting. Perhaps some bad fuel was the last straw.

Looked up the part number and will call the dealer in the morning to see how much plugs cost. It may just be a "may as well replace it" kind of thing.
 

D2Cat

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I just worked on my with some help from North Idaho Wolfman. I ended up with a bad connection at the middle GP. I removed all 3 GPs' and tested them on a battery. Takes about 15 seconds for them to begin to glow.

I should have begun by testing each connection with a test light, but didn't. I had to remove the intake manifold to get 2 of the GP's out, but that took only a few minutes. It came out under the fuel lines with no problems.

They're wired in series in these old tractors so if one is bad you have a weak link.
 

North Idaho Wolfman

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Dumb question time.

You keep saying gas... are you 100% sure that you used strait diesel?
Did you turn the fuel shut off back on after you changed the filter?
Have you taken off the line that feeds the injector pump?
Is it flowing fuel well to the pump?

White smoke is normally fuel flow is too high and it's flooding the pistons, or it's being feed fuel that it doesn't like. ;)
 
Last edited:

5thhorseman

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B7000, Allied 95 FEL, Sovema Tiller, Blade, on 3 overgrown acres
Oct 21, 2010
107
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16
Aldergrove, BC
Hey, all questions are good questions, and sometimes the dumb ones are the best.

You keep saying gas... are you 100% use it was strait diesel?
I shouldn't have said "gas". Bad habit. The old diesel I put in was from my largest jerry can which I only use for diesel and is labelled "diesel". When I got fresh diesel I am 100% sure I was using the diesel nozzle.

Did you turn the fuel shut off back on after you changed the filter?
Yes. Also, I have pushed a lot of diesel through the loosened injectors so I'm sure it's flowing all the way through.

Have you taken off the line that feeds the injector pump?
No, I haven't taken off any lines. I didn't think I needed to since since the fuel filter is below everything else so everything could be drained by removing it.

Is it flowing fuel well to the pump?
I'm not sure how to check for that. I thought I that if I bleed correctly at the fuel bleed valve between the filter and injection pump this shouldn't be a problem, right?
 

5thhorseman

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B7000, Allied 95 FEL, Sovema Tiller, Blade, on 3 overgrown acres
Oct 21, 2010
107
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Aldergrove, BC
They're wired in series in these old tractors so if one is bad you have a weak link.
Is the indicator light also in series with the GPs? So if the indicator glows then there should be current flowing throught the GPs. I guess I can trace the wires tomorrow to find out.
 

Tooljunkie

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I have a current tester, set on wire will indicate amps flowing through wire. Good for anything high draw. Have used it successfully for tracing short circuits too, points in direction of short. image.jpg
 

5thhorseman

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B7000, Allied 95 FEL, Sovema Tiller, Blade, on 3 overgrown acres
Oct 21, 2010
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Aldergrove, BC
Called the local auto parts with the NGK equivalent part number and found that glow plugs are about $12 each. So that falls in the "might as well replace" bucket for me, especially since this tractor is 40 years old and the hard starting has got to the point where the throttle needs to be at maximum!
 

North Idaho Wolfman

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I think you need to do a compression test, night be to the point where it needs a rebuild. ;)
 

coachgeo

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I would certainly like to do a compression test, just to see where it's at. Need to find a friend I can borrow a tester from :)
If you have a Harbor Freight near you their 40'ish dollar Diesel engine compression checker fits many Kubota's.
 

5thhorseman

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B7000, Allied 95 FEL, Sovema Tiller, Blade, on 3 overgrown acres
Oct 21, 2010
107
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Aldergrove, BC
If you have a Harbor Freight near you their 40'ish dollar Diesel engine compression checker fits many Kubota's.
Ooooh, and it's on sale now for $29.99 as well. Might be worth crossing the border to pick one up.

I took a look at the user manual available on the HF website and the Kubota adapter is 10 x 1.25. The glow plug thread size on the NGK website is Thread Size: 10mm, Thread Pitch: 1.25mm, so looks like it's compatible!
 

5thhorseman

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B7000, Allied 95 FEL, Sovema Tiller, Blade, on 3 overgrown acres
Oct 21, 2010
107
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16
Aldergrove, BC
Well, after dealing with all my winter preparations, burn piles, and Christmas, I finally have some time to look at the tractor again. I tested the glow plugs and they both glowed nicely, but I replaced them anyways. Also checked the voltage drop just before the plugs and that was fine, so it's not electrical.

It was recommended to me that I get the injectors tested and rebuilt if needed, so I think that'll be my next step.

Dealer quoted me $80.95 / $78.69 for new injectors (yes, each cylinder's injector has a different part number, weird!) and washers will be a couple of bucks, which is not too bad, so I wonder if it's just worth replacing them anyways, since this tractor is probably around 40 years old with god knows how many hours on it.
 

5thhorseman

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B7000, Allied 95 FEL, Sovema Tiller, Blade, on 3 overgrown acres
Oct 21, 2010
107
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Aldergrove, BC
Before ordering new injectors, I decided to recheck the fuel supply. Opened the bleed valve below the injection pump and fuel spurted out. Check. Then loosened the fuel lines at the top of the injectors. Fuel only coming out of one of the two.

So I removed the fuel lines entirely which was a major pain as some of the nuts just would not come loose, but in the end managed it. With the fuel lines off and the nuts on the ports backed off by 1/6 turn the fuel squirts up around 2", but fully tightened there is no squirting though I can still see fuel is being delivered as I can see it spilling out gradually.

Is this normal?
 

North Idaho Wolfman

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Sounds right,
When you put the injector line back on you will need to make sure you get all the air out, so tighten the pump side and leave the injector side loose, crank till fuel is present then retighten.
One note are you 100% sure it was diesel that you refueled with, seen and heard of fueling with gas and/or a mix, that will prevent it from starting.
 

5thhorseman

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B7000, Allied 95 FEL, Sovema Tiller, Blade, on 3 overgrown acres
Oct 21, 2010
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Aldergrove, BC
Went out and worked on it some more before I saw your post Wolfman. Fuel dribbling out after those nuts on the pump were tightened sounded alright to me too, so I went ahead and put it all together again, just like you said.

Was a pain getting one of the fuel lines to seat properly on the pump, as I had bent it quite a bit getting it off, but after a few tries and careful bending it's all in place and no leaks. Took quite a bit of cranking to get the fuel all the way to the top again.

Well wonder of wonders it started right up and runs beautifully now! I guess it was just some clogging on the injection pump ports. Haven't put a load on it yet as the air intake is still off, but it sounds better than ever.

So I guess I need to pick up a gasket for that then I`m good to go.

Is there anything for diesel engines to help clean up the injectors a bit, just in case there`s additional improvement there?
 

Tomcat

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B7000 4WD, RS1(?) rototiller, Konik 125 ATV
Nov 19, 2014
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Glad you got it fixed! I haven't run my B7000 dry (YET!) but it has been getting harder to start lately.
 

5thhorseman

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B7000, Allied 95 FEL, Sovema Tiller, Blade, on 3 overgrown acres
Oct 21, 2010
107
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16
Aldergrove, BC
Looking back on it now I understand a bit more. I used to think running dry was no big deal, cos I always managed to bleed and restart without any issue. Piece 'o cake!

I since learned that running dry means putting any crap at the bottom of the tank through the fuel system ... not a good idea. I'm thinking now that is what caused my starting issues as well. It got to the point where I had to have the throttle at max during startup!
 

Tomcat

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It got to the point where I had to have the throttle at max during startup!

About the same for me although not quite full throttle. I'm going to change my filter and bleed the system and see if it makes a difference.