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

[JJT]

Have any of the fuel lines been replaced with rubber? I've seen this same issue on a tractor with a collapsed fuel line. Ran for awhile, gets warm and then the rubber line collapses, shutting off the fuel.

 

[jimnor46]

It slows down smooth like it is running out of fuel., and has no power

My Mahindra did exactly the same thing, come to find out there was a strainer in the gas tank that wasn’t even shown in the owner’s manual. Someone on here told me about it. Strainer was almost completely stopped up. Took the d**n thing out and put an inline filter in and solved the problem.

 

[Garman906]

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.

I'll post again once I find out. Kubota tech was here this morning and he said it's getting air in the line somewhere. He told me to change the fuel filter assembly as they have a known issue with a crack developing on the back side. I don't think that is my problem, but I ordered a new one this morning just because I was already considering it. I'm still testing some other things. I will not let this beat me.

 

[Garman906]

Have any of the fuel lines been replaced with rubber? I've seen this same issue on a tractor with a collapsed fuel line. Ran for awhile, gets warm and then the rubber line collapses, shutting off the fuel.

I did replace the lines with rubber. I'm going to see if I can find some clear line so that I can see the fuel as it's moving through the system in case there is some air getting in.

 

[Garman906]

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.

I did use a gas can for diesel but that was after the fact and there could not have been more than a few drops in the can

 

[seville009]

I did use a gas can for diesel but that was after the fact and there could not have been more than a few drops in the can

i accidentally put same gas into my diesel tractor years ago. Probably had half diesel/half gas in it. Starting running really rough and stumbling pretty quick. That's why I asked at the beginning if it was stumbling or running smooth. It doesn't sound like you have gas in the system. In my case, I just drained the fuel, replaced the filter, put in diesel, labeled my containers very clearly, and it started and ran fine.

 

[Garman906]

I wanted to share a helpful "bush fix" hack that I came up with the other day when I was considering that I may still have something stuck in the fuel tank that might be floating around and blocking the feed port at the bottom of the tank. I took a piece of very small gauge wire like welding wire or similar and doubled it and shoved it into the nipple where the tank line connects all the way until it touches the back side of the tank with just a little sticking out in case you need to remove it. This will prevent any foreign object from completely covering the fuel outlet coming out of the tank but also will not block flow.

 

[newbury]

I'll post again once I find out. Kubota tech was here this morning and he said it's getting air in the line somewhere. He told me to change the fuel filter assembly as they have a known issue with a crack developing on the back side. I don't think that is my problem, but I ordered a new one this morning just because I was already considering it. I'm still testing some other things. I will not let this beat me.

Well keep us posted.
Did you try JWR's method?

 

[newbury]

Yes, in spite of the elusive nature of it I still say it is fuel issue. I don't see it being compression since compression doesn't stick around for 20 minutes and then fail... one thing that seems not to have been tried is to rig an alternate fuel source that bypasses everything else feeding right into the injection pump inlet (wherever the outflow of the lift pump goes.) May take a bit of effort but since this problem is worse than the average nuisance worth trying. I'd get some sort of fuel bladder or container, rig a fuel line from it direct to the injection pump and feed clean diesel fuel into it.

 

[RancherGuy]

... approximately 20 minutes worth and the engine lost power and slowed way down.

I read all of the posts and am curious about a couple of points. I have an L3710 - really like it. The fuel tank is at hood level, behind the instrument panel. Maybe I haven't researched enough, but I don't think I have an electric lift pump for fuel. The tank is above the injector, so my expectation is fuel is gravity fed to the fuel filter then into the injector. If air is introduced, then the injector is sucking, and that sucking means fuel restriction.

Now my main question - you have stated that you have drained the tank more than once. What is your definition of drained? Did you remove the tank to drain, or only use the tank outlet with the tank in place? if you have not removed the tank, I believe it is time. The fact that you have removed debris from the tank reinforces the suggestion. I have many experiences with tanks that get plugged at the tank outlet. Sometimes there is a screen, sometimes not. The remedy is removal and disassembly of the outlet fixture/connection. I wash the tank out with a garden hose then let it dry before reinstalling. A shop vac hose in the empty tank helps drying.