B7100 Injectors

[TxRzrBk]

I took my injectors from my 77 B7100D to an injector shop, they said they all need to be rebuilt because they are leaking and the cost to rebuild all 3 is $165!!

I am weighing having them rebuilt vs. buying new and here is what I find on new ones. One thing I am not sure of, the replacement injectors are called "nozzle holder", is this a complete injector or just the case?


Assuming these are complete injectors here is what I found.
The #1 injector with single overflow outlet original part number 15271-53000 is replaced by 70000-65208, these are $40.56 shipped. #2 and #3 injectors are original part number 15271-53020 replaced by 70000-65209, these are $63.91 shipped.
I am assuming that the only difference between the two parts is the overflow on #2 & #3 being a Y ?

2 questions
1) any benefit in having my original injectors rebuilt?
2) would it work to order 3 #1 injectors (70000-65208) and use my original Y overflow fitting?

With option 2 above total cost would be $121.69 whereas rebuilding my injectors is $165, I would save $43.31.

edit - looks like 70000-65208 does not come with the hose barb ring (see attached pictures) while 70000-65209 comes with the Y hose barb ring.

Would appreciate if anyone can comment as to pros/cons of new vs. rebuilt injectors.

 

[North Idaho Wolfman]

I don't know where you got the part# 70000-65209 , but that's the wrong # for that motor
You want the 70000-65208, that is the right injector for all three cyl. in both the old and new serial numbered tractors.

Oh yea, I would go new.

 

[TxRzrBk]

Thanks, and to answer your question I got it from a well known online parts vendor who's name starts with and M. See attached image

 

[North Idaho Wolfman]

This situation is where I trust the factory manuals over aftermarket!


The difference is that there was 2 different return line setups, Mine uses a solid steel line set and newer injectors used rubber ones.

I would save the funds and get the cheaper ones and reuse your fittings.

 

[TxRzrBk]

Got the new injectors installed and something is wrong. I had a really hard time getting it to start so I back tracked and bled the system again which didn't seem to help. Once it started it was running horribly and smoking like I have never seen it smoke before, thick white smoke. I ran it for about a minute thinking the assembly lube in the new injectors needed to burn off but it did not seem to dissipate. It was also leaking from the fuel line on top of the #3 injector so I shut it down and figured I better regroup before I try it again. Any ideas?

 

[North Idaho Wolfman]

Where did you buy the injectors from? What part # did you order and what part # did you get? Did they physically match the ones you took out to a tee? Did you make sure to get the copper sealing rings too, or did they come with them? Did you have to reuse any part of the old injectors?

 

[TxRzrBk]

The injectors are kubota 70000-65208 purchased from ebay and appear 100% identical to the originals. I purchased and installed new cooper sealing washers. The only part I reused from the old injectors is the overflow hose barb rings. Injector threads were lightly oiled and torqued to 35 ft/lb. I have a feeling 35 ft/lb isn't getting the new washers to seal, the only other thing I could see being wrong is maybe air in the system but I bled it 2 times. Another random thought, is the orientation of the washers important?

 

[North Idaho Wolfman]

Sounds like you have a bad injector, the white smoke is from it flooding the cylinder.
You can pull the injectors and look for a wet combustion chamber or maybe chambers.

Another way to tell is to loosen the injector lines one at a time while it's running if the RPM's don't change or the increase at any point then that your bad injector.

 

[TxRzrBk]

I guess that makes sense. As bad as the smoke is I am guessing it is a severe leak and it shouldn't be too hard to figure out which one it is. If more than one of the injectors was faulty wouldn't it be causing it to rev?

 

[North Idaho Wolfman]

I guess that makes sense. As bad as the smoke is I am guessing it is a severe leak and it shouldn't be too hard to figure out which one it is. If more than one of the injectors was faulty wouldn't it be causing it to rev?

Surprisingly an over abundance of diesel will cause it to run slower!
I pulled a bone head move a while ago, pulled the injectors and cleaned them, when I put them back together I put the valve in upside down, they free flowed diesel in, it did start although it smoked like mad and would not idle, had me scratching my head for a few minutes till I realized what I did.

 

[TxRzrBk]

Thanks for all the help. I really don't want to wait for shipping of replacements, given the severity of the leak I would tend to think that one or more of them is stuck open either from lack of assembly lube or being handled rough during shipping. I am going to try to figure out which injector(s) are leaking and see if I can disassemble without creating any tool marks.

 

[TxRzrBk]

Just thought of one other potential cause. Do the washers that go under the overflow hose barbs need to be oriented in a particular way? My theory was that the overflow might be blocked causing the injectors to get excess fuel. On my old injectors the washers were stuck in place and I never messed with them.

 

[TxRzrBk]

I have done everything I know to do and these injectors seem to be dumping entirely too much fuel for the engine to handle, I am either so lucky that I got 3 defective injectors or despite looking the same these are the wrong injectors. The only marking on the injector is "2170" on the body. Anyone know how to cross this back to a kubota part number.

 

[North Idaho Wolfman]

Have you taken them apart?
Here is a part layout to compare with.
#7 is cupped on one end and should point down.

 

[TxRzrBk]

I have not taken them apart out of fear that the vendor won't give me a refund if I can't fix them. I started it for a brief moment today and did not get any overflow, I checked all of the overflow lines and they are clear. In the morning I am going to try to connect each injector to a fuel line turned to the side and visually check for leaks.

I haven't touched the injection pump except for removal of the fuel lines, the only thing that happened during that process was that the fitting on the #1 injector came loose and I had to snug it back down before I put the lines back on. You figure I could have created any problems here?

 

[kuboman]

Injectors are a precise unit and my bet is you have the wrong injectors. Best bet is either take your old ones and have them rebuilt or take your new ones to a shop and have them set to your engine.

 

[TxRzrBk]

I contacted the vendor and verified that these are brand new kubota injectors. I have asked them to double check the "2170" marked on the exterior matches the part I ordered.

 

[kuboman]

I contacted the vendor and verified that these are brand new kubota injectors. I have asked them to double check the "2170" marked on the exterior matches the part I ordered.

They can still be the wrong injector. I believe the number you refer to is just a body number.

 

[TxRzrBk]

They can still be the wrong injector. I believe the number you refer to is just a body number.

I agree, 2170 is actually stamped into the side of the nozzle holder.

 

[kuboman]

A good diesel shop will be able to check your new injectors and tell you if they are correct for your engine.