Case700 run away

[Wyathall]

I recently bought a case 700 diesel or 701b.
I was driving it down the road in road gear at about half throttle when it just took off running fast than full throttle and I couldn't shut it off. I had to choke the air off to get it to kill. I took a cover off the injection pump where the throttle is and everything looks like it works normal and after a month of sitting the tractor seems to work normally but I still don't trust it, just wondering if anyone could maybe point out the problem.

 

[chris142]

was it running on diesel fuel or motor oil?

 

[Wyathall]

IDK where the motor oil would be coming from so I really don't know I was in a hurry trying to get it shut down before I would be rebuilding a motor.

 

[used red MN]

was it running on diesel fuel or motor oil?

Chris, just FYI or maybe you know this a 701B does not have a turbocharger so the common oil supply from a faulty turbo bearing seal or bearing that usually is the fuel for a runaway diesel does not apply here.
Wyatt.., welcome to YT! Does this tractor have an oil bath air cleaner? If that has gotten water in it to raise the oil level there is a possibility that this could be the source of oil that ran your engine uncontrollably. Secondly, if you had the perfect storm of bad valve guides and the drain back for oil from the rocket arm above the head being plugged it might get oil in the intake to run it then but it would only get into the two cylinders under that valve cover.
After all that I would guess some malfunction in the injection pump was the real problem. If I do this @Dieseltech, that should alert the resident injection pump repair guy to possibly stop by to give his two cents.

 

[Wyathall]

The valve guides shouldn't be bad because this engine never burned any oil, this was our neighbors go to haying tractor and every time I have seen it and for last month or 2 that I owed it there has never been any type of smoke nor have I had to add oil.

The oil bath air clean intrigues me because I changed the oil the previous morning and I remember it was about 1/4 inch over and I didn't think that would make any difference.

 

[jon f mn]

That should have the bosh rotary pump on it. They are known to have sticky throttle shafts. Altho it is uncommon to happen if they were working, usually shows up on start up. The shaft is under the side cover just below the head. Take that cover off and see if the shaft moves when the throttle is moved. If not you can try working it back and forth some to get it loose. If you need to take it out be very careful as there is a very small spring in there that can easily get lost. Just clean the shaft with carb cleaner or something and a wrap, do not polish it as it has very tight tolerances.

 

[Wyathall]

We had that problem when we first started it after the winter the throttle was stuck closed, I just tried and it seems to be working fine.

 

[tomturkey]

Chris, just FYI or maybe you know this a 701B does not have a turbocharger so the common oil supply from a faulty turbo bearing seal or bearing that usually is the fuel for a runaway diesel does not apply here.
Wyatt.., welcome to YT! Does this tractor have an oil bath air cleaner? If that has gotten water in it to raise the oil level there is a possibility that this could be the source of oil that ran your engine uncontrollably. Secondly, if you had the perfect storm of bad valve guides and the drain back for oil from the rocket arm above the head being plugged it might get oil in the intake to run it then but it would only get into the two cylinders under that valve cover.
After all that I would guess some malfunction in the injection pump was the real problem. If I do this @Dieseltech, that should alert the resident injection pump repair guy to possibly stop by to give his two cents.

Reminder that Rich(Dieseltech) is recovering from a stroke and may not be watching the way he normally did!! Wishing him a speedy recovery. He just talked me thru a similar problem with a Racine 400 diesel. the throttle governor control rod was sticky and would not react to the throttle or governor. Carefully removed and cleaned, Another Dieseltech satisfied customer. gobble