Kubota L3710 runs for 20 minutes then won't run at speed or at all.

   / Kubota L3710 runs for 20 minutes then won't run at speed or at all. #31  
You have some crap floating around in the fuel tank that takes a while to get sucked into the fuel intake line. It is big enough to plug the line and will not flow through into the filter. When you shut the engine down it drops off and will float around until the fuel flow pulls it back into the discharge again.

If you can see into the tank you can use a turkey baster with a piece of hose attached to try to get the offending object out of the tank.
 
   / Kubota L3710 runs for 20 minutes then won't run at speed or at all.
  • Thread Starter
#32  
JWR said:
I don't think the injection pump needs any positive pressure. To my knowledge the lift pump is only there because the injection pump lacks enough "sucking ability" at its' input to guarantee continual operation when on hillsides and other odd angles. The gravity pressure from a suspended "IV drip" would satisfy the injection pump -- I'm pretty sure. There's a lot of diesel tractors out there that do not have a lift pump.
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Thanks, that is good to know.
 
   / Kubota L3710 runs for 20 minutes then won't run at speed or at all.
  • Thread Starter
#33  
seville009 said:
Look at post #18 in this thread - he found his problem to be a piece of cardboard for packing purposes in the fuel filter.

long shot, but worth looking at your fuel filter just to check.

www.tractorforum.com

Diesel runs great for 1/2 hour then very low power.

www.tractorforum.com www.tractorforum.com
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I've had the filter assembly off and totally disassembled and I've checked the filter element several times. The threads on the bolts are starting to get worn with as much as I've turned them. My biggest fear is it's going to be something really simple that I have overlooked.
 
   / Kubota L3710 runs for 20 minutes then won't run at speed or at all. #34  
Can you disconnect the fuel line from the tank and pipe it into a container then let the fuel just run out of the tank for a while? to see if there is something that stops up after a few minutes? I would guess there is maybe something in the line between the filter and the tank. The tractor burns the fuel that is available then it takes time to drizzle in more fuel before it will run again, like a restriction of some sort maybe. I am a simple man and can only see simple solutions... I am not clever enough to see the technical stuff.
 
   / Kubota L3710 runs for 20 minutes then won't run at speed or at all.
  • Thread Starter
#35  
I verified that fuel is present at the injector pump today. When the engine started acting up, i took the bleeder line loose from the fuel input on the injector pump and opened the bleeder valve. Fuel was coming out of the bleeder valve in what appeared to be sufficient quantity and the engine tried to die with it opened. When it's running ok, I can open that valve and the engine slows a bit but doesn't die. I called the local dealer and asked for a mechanic to come diagnose the issue. I feel it's over my head at this point.
 
   / Kubota L3710 runs for 20 minutes then won't run at speed or at all.
  • Thread Starter
#36  
Jeff Lary said:
Can you disconnect the fuel line from the tank and pipe it into a container then let the fuel just run out of the tank for a while? to see if there is something that stops up after a few minutes? I would guess there is maybe something in the line between the filter and the tank. The tractor burns the fuel that is available then it takes time to drizzle in more fuel before it will run again, like a restriction of some sort maybe. I am a simple man and can only see simple solutions... I am not clever enough to see the technical stuff.
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I've drained the tank several times and the fuel flows freely. I am a simple man too and thought this would be a simple problem and it still may be but I'm not seeing it.
 
   / Kubota L3710 runs for 20 minutes then won't run at speed or at all.
  • Thread Starter
#37  
Garman906 said:
I verified that fuel is present at the injector pump today. When the engine started acting up, i took the bleeder line loose from the fuel input on the injector pump and opened the bleeder valve. Fuel was coming out of the bleeder valve in what appeared to be sufficient quantity and the engine tried to die with it opened. When it's running ok, I can open that valve and the engine slows a bit but doesn't die. I called the local dealer and asked for a mechanic to come diagnose the issue. I feel it's over my head at this point. I do appreciate everybody's input and just for caring enough to try to help a fellow out. I'll come back and post if It gets resolved.
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   / Kubota L3710 runs for 20 minutes then won't run at speed or at all. #38  
They say that "when you hear hoof beat think horses not zebras" but that seldom works for me I hope it turns out to be a simple fix for you.
 
   / Kubota L3710 runs for 20 minutes then won't run at speed or at all. #39  
I hope you find the problem, be sure to let us know, I have an Old L2650 kabota sitting for 2 years with the exact same problem.
 
   / Kubota L3710 runs for 20 minutes then won't run at speed or at all. #40  
A friend of mine called me a few years ago with a similar problem on an older Kubota. I had no clue so looked on the internet. Said it was either overheating or gas in the diesel fuel. I could not see any water in the radiator, but that did not help. I smelled the fuel and could detect a gas smell. He insisted it did not have gas in it. He finally drained the fuel out and put new Diesel fuel in and it ran fine. He still was not convinced so he put the old fuel in his diesel lawn tractor.Thirty minutes later it shut down just like his tractor. you may have already put fresh fuel in but I did not see it in your post. good luck.
 
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