Kubota GR2120 losing power when hot

[thclimer]

Hi all,

Just wanted to update here to let you know what happened and also help anyone else that comes across this thread in future. Long story short - the various posters above were right on the money, it was the first of the two fuel filters, located behind the rear left wheel. I swapped out the filter and after a bit of rough running whilst the air worked its way through the fuel lines, all is well. Mowed the whole of our property without so much as a hiccup.

Notes about the process:

- The filter is the first thing in the fuel line from the tank - so you need to clamp the flexible pipe that feeds it BEFORE you remove it. Yes, I worked that out the hard way.
- An impact driver with a long extension bar makes removing and reinstalling the filter much easier. The bolt holding the clamp is partially obscured, but I was able to get to it without removing anything with a bit of persistence.

Hopefully this will save someone some time in future anyway - thanks to everyone for your support, made all the difference!

Thanks for letting us know and it a good reference for anyone in the future. Glad your back running!

 

[Oxonmow]

Hi all,

Just wanted to update here to let you know what happened and also help anyone else that comes across this thread in future. Long story short - the various posters above were right on the money, it was the first of the two fuel filters, located behind the rear left wheel. I swapped out the filter and after a bit of rough running whilst the air worked its way through the fuel lines, all is well. Mowed the whole of our property without so much as a hiccup.

Notes about the process:

- The filter is the first thing in the fuel line from the tank - so you need to clamp the flexible pipe that feeds it BEFORE you remove it. Yes, I worked that out the hard way.
- An impact driver with a long extension bar makes removing and reinstalling the filter much easier. The bolt holding the clamp is partially obscured, but I was able to get to it without removing anything with a bit of persistence.

Hopefully this will save someone some time in future anyway - thanks to everyone for your support, made all the difference!

Hi, great thread, as i am having exactly the same issue. The problem is that i have just replaced both of the fuel filters. I am sure it is a fuel supply issue which is causing the rough running. However it inly happens after 20 minutes or so. Is it a fuel pump issue? Any ideas greatly appreciated. Only 550 hours on the tractor.

 

[pumasong]

If the symptoms sound the same - and you've eliminated the possibility of overheating - unfortunately I reckon you'll have to continue where I thankfully managed to stop. E.g. drain or bypass the tank and see what happens. Maybe you could do a bit of temporary plumbing from a fuel can to one of the new filters? That would eliminate the tank from the investigation.

If the pump was bad I would imagine the symptoms would be the same, not sure how you could identify that without swapping it out (which would be expensive if it's not that). Presume there's no additional smoke/heat/smells etc - if there are I would guess it's something else...

Good luck finding it - took me a while!

 

[gsganzer]

Hi, great thread, as i am having exactly the same issue. The problem is that i have just replaced both of the fuel filters. I am sure it is a fuel supply issue which is causing the rough running. However it inly happens after 20 minutes or so. Is it a fuel pump issue? Any ideas greatly appreciated. Only 550 hours on the tractor.

Seeing as you've changed the filters, I'd check for the tank not venting.

I had the same issues as the original poster, on my BX, and like the OP it was the filters. But I can see a non-venting tank or collapsed/restricted fuel line acting the same way.

 

[pumasong]

I'm guessing you've already tried opening the tank when it's happening? That would rule out tank venting and super easy to test. Other than that a pinched fuel line somewhere sounds plausible.

 

[SPYDERLK]

Hi, great thread, as i am having exactly the same issue. The problem is that i have just replaced both of the fuel filters. I am sure it is a fuel supply issue which is causing the rough running. However it inly happens after 20 minutes or so. Is it a fuel pump issue? Any ideas greatly appreciated. Only 550 hours on the tractor.

Did the problem take longer to reoccur after you changed the filters, or the same?
The mechanism by which a partially plugged filter causes a repeated delayed reaction is that the filter pleating slowly gets sucked shut as the tractor tries to get enough fuel under load. Then when you stop the suction goes away and the filter expands again. - Repeat. --- for this to be happening on the old filters, and then again on the new I think you may be dealing with a contaminating medium like water in the fuel. Could be just a couple drops of raw condensate got into that new filter and made it water wet. You can confirm this pretty easy.

Drain most of your fuel, add an alcohol containing "Dry Gas" to a few quarts of new fuel and put that in the tank. Start the tractor and let it idle for 15 minutes or more. Stop it for a few minutes then restart and use it. The problem should be noticeably improved, or even "cured" if it was water. Even if "cured" you may want the go ahead and change that 1st filter again. Its pleating has been sprained.