"Run away" Kubota engine

Apogee

Member

Equipment
B6100, B7100, B8200, B9200, G4200, L175, L35
Jan 22, 2012
518
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16
Tacoma, WA
Are you sure somebody hasn't worked on this before and perhaps left out one of the return springs? Your governor assembly will be a little different than the pic because it's a generator, but it should still have the springs in there. If one or both are missing, I'd bet you've found your problem.

Not sure I believe the groove story on the rack. I'd be taking a long hard look at the rack once the pump is out. If there really is a groove, it might be something that can be cleaned up in 2 minutes with a small file. It will likely be a sharp edge that's hanging up and "sticking." Oregon Fuel Injection will repair that pump for considerably less than buying a new one. Call them. And no, I don't have any affiliation with them.

You really need the proper exploded diagram for your engine from the Industrial side of Kubota. Then you'd know exactly what should be where.

#10 in the attached diagram is called a "Spring(start)" and #20 is called a "Governor Spring." If either of the springs are damaged (stretched) or missing, it *could be* that the rack is moving too far to the open position and could be hanging up because it's moving beyond where it should during start. This is just a guess, but this is what I'd be looking for.

Wolfman or one of the other techs on here might have experience with the groove wearing into the rack issue. I don't. I tend to have healthy skepticism of most dealers unless you know you can trust them. Often they just want to sell expensive parts. It would be a bummer if you bought a new pump only to find out that the problem was really a missing or damaged return spring that cost a buck.

Hope this helps,

Steve
 

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707pc50

New member
Feb 7, 2015
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Arcata california
When we first tore into it it didn't pear to have every been worked on, but I bought it sat auction so I have n way of know what really happened. I don't know a ton about these engines but the dealer printed the blow up for me and it seemed all to be right on the governor, but no I'm not positive.

Since I have a parts engine that was running when retired, just getting old, I am thinking why not swap the injector pump and see if that does it?

From that blowup looks like swapping the injection pump is just those four bolts and the unit lifts out and replacement drops in? Does this seem right?

thank for all the advice
 
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Apogee

Member

Equipment
B6100, B7100, B8200, B9200, G4200, L175, L35
Jan 22, 2012
518
0
16
Tacoma, WA
Pretty much. It's not a big deal. At least it would give you a place to start from as long as you know the pump is good. Just be careful to make sure you engage the rack correctly. Also, if the rack is stuck at one extreme, you will likely need to unstick it before it will clear the opening in the block.

If after swapping it pukes lots of smoke or is way down on power, then you'll know the pumping timing needs to be adjusted.

But yeah, give it a go. The existing pump needs to come out one way or the other. But take a close look at it to see if you can figure out where it's hanging up. You might easily be able to fix it, then you'd be golden.

Not sure how much the dealer quoted on a new pump, but here is the link to OFI just in case you end up needing it. If you end up needing a pump, make sure to ask the difference in price between a new and rebuilt unit. Sometimes it's not much...

http://oregonfuelinjection.com/index.php?pid=65

You're getting there!

Good luck!

Steve
 
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Apogee

Member

Equipment
B6100, B7100, B8200, B9200, G4200, L175, L35
Jan 22, 2012
518
0
16
Tacoma, WA
One last thing, make sure you run some sort of diesel fuel treatment. The Stanadyne stuff is very good and is what OFI recommends.

The new low sulphur diesel fuel doesn't provide the lubrication needed by the older engines that's why you should add it. You can search on this site (or the web) for lots of info about this.

Food for thought.
 

707pc50

New member
Feb 7, 2015
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Arcata california
Cool thanks, I talked to dealer I'm gonna bring in my old engine they are gonna pull pump and swap it in, hopefully it works, this has been a pain, I'm not convinced fully this is gonna do it, but I will ask to see the worn/bad part on the old pump, we'll see at least this way I'm saving the 800 for a pump. Thanks for the help I'll let you know how it goes.
 

North Idaho Wolfman

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Jun 9, 2013
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Cool thanks, I talked to dealer I'm gonna bring in my old engine they are gonna pull pump and swap it in, hopefully it works, this has been a pain, I'm not convinced fully this is gonna do it, but I will ask to see the worn/bad part on the old pump, we'll see at least this way I'm saving the 800 for a pump. Thanks for the help I'll let you know how it goes.
If the problem is in the injection pump, which it sounds like it is, you won't be able to see it with your eyes! ;)
 

707pc50

New member
Feb 7, 2015
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Arcata california
Ok good to know, I can usually maintain these engines but I don't know a ton Bout the internals, so thanks for that. I'm dropping the donor engine off in the am and I think the gaskets should be in with in a day or two. I'll have some updates for you guys soon, thanks for all the advice it is nice to have a few sources to bounce ideas off.
 

707pc50

New member
Feb 7, 2015
37
0
0
Arcata california
The dealer swapped the fuel injection pump from my parts machine over and the generator is not running away anymore. Having a issue with the electric fan not running, but got it going by direct wiring so must be a sensor or relay thing... But the main thing is gen is running good. Thanks for all the help here, sure is nice having this resource here, being able to ask questions to people who know what's going on and discuss with people all over the place is nice.
 

Apogee

Member

Equipment
B6100, B7100, B8200, B9200, G4200, L175, L35
Jan 22, 2012
518
0
16
Tacoma, WA
Excellent!

A bit of a hassle but very glad your deal is going to work out.

Nice work!

Steve