# John Deere 6068HF275 Surging



## Versius (Jan 9, 2020)

I have a generator (Wacker G160) that is giving me fits. It is a little bit hard to start, but not horribly so. Once it starts, it surges up and down very quickly (every second or so) and blows with a lot of force out of the exhaust (if you have it below a tree, it moves even fairly large limbs). The smoke is both black and white and it is considerably louder than it should be. This is in idle, without the generator engaged. It has a 6068HF275 engine. The first mechanic told me it was the injection pump (rotary) and we had that replaced at a cost of 3700. Same problem still. Then I was told it was probably the injectors. I bought new ones and had them installed. Same problem. Then I was told it was probably air in the lines or an air leak. I noticed at this point that the fuel line fittings had rubber in them that was very dry rotted, so I went down to the John Deere dealer and bought a new complete set (800 dollars) and replaced the fuel filter and water separator, at which point I couldnt get the water separator "cap" that goes around the filter to screw back on straight, so I bought a new assembly and mounted it. I also replaced the small mechanical fuel pump that is between the two filters. Same problem. Exactly. It is no different. I also noticed while doing all this that the radiator had a bunch of fins missing (although it wasn't leaking), so I pulled the radiator and intercooler to get the radiator recored, so I'm waiting on that right now. While I was pulling that, I had to take the muffler out to get to it and I noticed that the inside of the exhaust pipes has about an eighth of an inch of hard black deposits on it that is glossy black and there,was some black soot in the pipes loose as well. My mind is blanking on me, so I can't remember the name of the part, but the crankcase oil catcher? That part doesn't seem to have any significant amount of oil in it. I will be recounting the radiator and intercooler on Monday or Tuesday and am hoping to diagnose whatever this problem is as soon thereafter as possible and was hoping someone might have a good idea. I thought it might be bad diesel, so I put the inlet hose directly into a tank of new diesel and ran it for about 30 minutes with no difference as well. Thank you in advance for any ideas or help that anyone can give me. I am pulling out my hair here, lol.


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## pogobill (Jan 31, 2012)

That's quite a genset you have there! Could be a governor issue, fuel issue or failing parts. You've certainly poured a bit of money into this unit and have completed may repairs. How are the air filters? Could be contributing to the smoke issue. Is there a governor on this thing? Perhaps just an engine speed sensor (#GM49939) that is causing you grief. Do you have a manual for the engine?
http://resources.kohler.com/power/kohler/industrial/pdf/tp6291.pdf

You really need someone to do a little trouble shooting rather than throwing expensive parts at it. There are a few great diesel guys here that I am sure would enjoy helping you do a little trouble shooting. Welcome to the forum and hang in there!


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## Versius (Jan 9, 2020)

Thank you so much for the reply. The way I understand it, it has some type of governor in the injection pump. All the filters, including the air filter, are new and we have already changed the injection pump. I thought it might be something in the computer, but we actually have two of the exact same units and I pulled the computer off the other one and plugged it in and it does the same thing. And, yes, I agree that thid throwing expensive parts at the problem isnt the best way forward. Unfortunately, the two mechanics I've taken it to so far have been unable to figure it out. As far a a speed sensor: I'm going to look at that; it sounds like a good idea. I'm afraid I'm really not much of a mechanic, although I have repaired a lot of things over the years. Any and all help is greatly appreciated. I've been trying to get this unit back up for months and I'm way too much money into it at this point, but at least it will have a new fuel system when we do figure out the problem and hopefully I wont have to worry about that for a while anyway.


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## Versius (Jan 9, 2020)

I do have a manual for the generator. Not for the engine. Its a 6068hf275 John Deere


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## Versius (Jan 9, 2020)

The one you posted does look identical though, so I guess I do now; thanks again.


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## thepumpguysc (Jan 25, 2015)

If u can get me the #'s off the inj. pump name plate, I might be able to tell u how to adjust the surge out..


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## Versius (Jan 9, 2020)

thepumpguysc said:


> If u can get me the #'s off the inj. pump name plate, I might be able to tell u how to adjust the surge out..


I can get that this evening. Thank you for the reply and any help as well.


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## thepumpguysc (Jan 25, 2015)

If its a Stanadyne inj. pump, 99% of them that went on gensets have an adjustable load spring.. Its the adjustment between the top cover & the steel lines.. the "stud" that lies directly between them..
I STILL NEED the #'s..


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