L2501 losing power

mikeyt

New member

Equipment
L2501
Apr 25, 2023
12
10
3
NC
Been in the shop. They claim to have sent injectors out to be checked. Ran good for a few hours then same.

I just removed fuel tank and cleaned it. Little bit of debris not much. One half inch clump of goo.
No water in fuel.

Ran great for about 20 minutes.
Seems to come and go. It will barely have enough power to push into a pile of gravel then it will pick up a little power for a few minutes then back to missing and loss of power.
Seems to idle ok but if I throttle up I can hear it struggling.

New fuel
New fuel filter
New Air filter
Fuel tank cleaned

It's still under warranty but my local shop is struggling right now. Took 2 months to get the injectors checked.

Any guesses?

Thanks
 

jimh406

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Lifetime Member

Equipment
Kubota L2501 with R4 tires
Jan 29, 2021
2,356
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Western MT
I would go buy a bottle of Powerservice Diesel Kleen Grey diesel fuel additive and a bottle of Seafoam, add it to the tank, and run it. You likely still have some goo in the system. The Powerservice with added cetane and the other additives along with the Seafoam will help clean it out. Neither will hurt the fuel system, fuel pump, or injectors.

Fuel pumps don't run intermittently on their own, but the pressure could fluctuate with goo in the system or partially clogging the filter.

Then, from now on, use an additive like PowerService Diesel Kleen either Summer or Winter formula from now on. It only takes a bit to keep the fuel from developing algae/bio growth.
 
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007kubotaguy

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B7100DT L245DT JD 2355
Dec 23, 2012
643
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Herald Calif.
Remove the lines from the fuel pump. Plug the line coming from the tank so you don't lose fuel. Put your finger over the inlet side of the fuel pump. Crank the engine. Fuel pump should create a vacuum and hold. If it does not the fuel pump is bad. I have replaced a lot of fuel pumps on these machines where the check valves inside of the pump pop out. Have the same symptoms you're talking about. It's a quick easy test.
 
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mikeyt

New member

Equipment
L2501
Apr 25, 2023
12
10
3
NC
Thanks for the replies!
I've been running K100 additive the last few tank fulls since this started.
Spoke with service manager at a dealer and she said there are 2 grommets that get clogged easily. One at the bottom of the tank. Which I did not know about but hopefully my kero shake cleaned it out. Fuel flowed good out of hose when disconnected.

The other is in the filter housing.

I will do the fuel pump test too as soon as I get a helper.

She said to strain the fuel when filling the tank. Apparently the screen in the funnel ain't enough.
Kind of disappointed in this design if that's what causes this.
 

The Evil Twin

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Equipment
L2501, LA526,
Jul 19, 2022
2,817
2,830
113
Virginia
Somewhere around here someone posted a stainless coffee strainer that fits in the filler neck.
Never had an issue myself. However, I don't fill up out in the bush. Always back at the shop and after wiping down the Guelph cap and filler neck before taking the cap off.
Guess it wouldn't hurt to put one of the Java screens in though.
 
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jimh406

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Equipment
Kubota L2501 with R4 tires
Jan 29, 2021
2,356
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Western MT
She said to strain the fuel when filling the tank. Apparently the screen in the funnel ain't enough.
Kind of disappointed in this design if that's what causes this.
I'm not opposed to straining although I doubt there is a reasonable filter that's going to eliminate the issue. Straining will filter large particles.

You need an additive to prevent the organisms from creating the sludge in the tank and to break it up. Realistically, there isn't any normal strainer that's going to help if the fuel sits for an extended period of time.
 

MapleLeafFarmer

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Equipment
Lots incl. B and L kubotas
Dec 2, 2019
632
487
63
E.
Thanks for the replies!
I've been running K100 additive the last few tank fulls since this started.
Spoke with service manager at a dealer and she said there are 2 grommets that get clogged easily. One at the bottom of the tank. Which I did not know about but hopefully my kero shake cleaned it out. Fuel flowed good out of hose when disconnected.

The other is in the filter housing.

I will do the fuel pump test too as soon as I get a helper.

She said to strain the fuel when filling the tank. Apparently the screen in the funnel ain't enough.
Kind of disappointed in this design if that's what causes this.
how old is your tractor and how many hours on it? This will help us see how fresh you keep your fuel.

What type of fuel do you use? What percentage of bio diesel you may be using. (B100 to B0 available)

Do you always use same fuel or have you recently switched? Have you recently switched to high B bio diesel.

I dislike bio diesel. I have never had any problems as I keep my fuel fresh, I store most of my machines inside somewhat away from cold/hot temps, and my fuel rarely sits in tanks long.
Bio diesel is not fond and more sensitive to cold weather, not fond of moisture, not kind to certain types of rubber hoses, higher cleaning properties can clog small orifices so take care if not using for long period of time then all of a sudden switch to a high B biodiesel as next thing you know stuff gets plugged, more capable of growing bacteria and fungus in your tank, etc... than regular diesel

Who and how did the tech clean your tank? was the tank removed and flushed or do you mean it was dirty/gummy and someone just high dosed it with a cleaner and hoped the gunk/sludge would drain by itself?

just guessing without more info but maybe your cleaner you have just started to use is causing the problem worse by rapid flushing the "junk" too quickly into some small place that couldn't handle it all of a sudden.
 
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mikeyt

New member

Equipment
L2501
Apr 25, 2023
12
10
3
NC
Somewhere around here someone posted a stainless coffee strainer that fits in the filler neck.
Never had an issue myself. However, I don't fill up out in the bush. Always back at the shop and after wiping down the Guelph cap and filler neck before taking the cap off.
Guess it wouldn't hurt to put one of the Java screens in though.
My funnel has a built in screen that's pretty fine.
I've filled up at the gas station also which she said could cause it as the nozzles can introduce crap in the fuel. So who knows where it came from?
The filler cap gets nasty too. I try to be careful not to let the tuff fall in the tank though.
 

mikeyt

New member

Equipment
L2501
Apr 25, 2023
12
10
3
NC
how old is your tractor and how many hours on it? This will help us see how fresh you keep your fuel.
About a year old. Almost 170 hrs

What type of fuel do you use? What percentage of bio diesel you may be using. (B100 to B0 available)
Green diesel from gas stations and off road when I can.

Do you always use same fuel or have you recently switched? Have you recently switched to high B bio diesel.
Fuel comes from different places. No bio diesel

I dislike bio diesel. I have never had any problems as I keep my fuel fresh, I store most of my machines inside somewhat away from cold/hot temps, and my fuel rarely sits in tanks long.
Bio diesel is not fond and more sensitive to cold weather, not fond of moisture, not kind to certain types of rubber hoses, higher cleaning properties can clog small orifices so take care if not using for long period of time then all of a sudden switch to a high B biodiesel as next thing you know stuff gets plugged, more capable of growing bacteria and fungus in your tank, etc... than regular diesel

Who and how did the tech clean your tank? was the tank removed and flushed or do you mean it was dirty/gummy and someone just high dosed it with a cleaner and hoped the gunk/sludge would drain by itself?

I pulled the tank and flushed it myself.
I didn't start using additive until the problem started.

just guessing without more info but maybe your cleaner you have just started to use is causing the problem worse by rapid flushing the "junk" too quickly into some small place that couldn't handle it all of a sudden.

See replies above
 

The Evil Twin

Well-known member

Equipment
L2501, LA526,
Jul 19, 2022
2,817
2,830
113
Virginia
My funnel has a built in screen that's pretty fine.
I've filled up at the gas station also which she said could cause it as the nozzles can introduce crap in the fuel. So who knows where it came from?
The filler cap gets nasty too. I try to be careful not to let the tuff fall in the tank though.
Yeah, I have one of those funnels to. Problem is, I can't see the fuel level as I'm pouring. Hence, the reason I just stick the nozzle in and pour away.
 

Rdrcr

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Lifetime Member

Equipment
L2501 w/ S2T Turbo Kit = 35 PTO HP (Current), B2601 (Sold)
May 7, 2021
670
738
93
WA
Remove the lines from the fuel pump. Plug the line coming from the tank so you don't lose fuel. Put your finger over the inlet side of the fuel pump. Crank the engine. Fuel pump should create a vacuum and hold. If it does not the fuel pump is bad. I have replaced a lot of fuel pumps on these machines where the check valves inside of the pump pop out. Have the same symptoms you're talking about. It's a quick easy test.
I think I've read about some L2501 owners experiencing troubles with the fuel pumps on the D1703 in the past. I'm curious to know if this is the cause of the OP's issue.

Mike
 
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mikeyt

New member

Equipment
L2501
Apr 25, 2023
12
10
3
NC
Next time I have a few hours I'm gonna do the test and clean the filter housing and see what happens.
Will report back
 

PaulL

Well-known member

Equipment
B2601
Jul 17, 2017
2,439
1,364
113
NZ
People with similar issues it tends to be filters, injectors or some other part clogging up. Once you have gunk it seems that you clean and replace everything, and then it all gunks up again once it's running as gunk comes out of corners that you didn't think to clean. I've seen people go through that dance 2-3 times before it's all clear.

There's also the option to blow compressed air back up the line into the tank, and then recheck everything downstream.

Ultimately you need to know you have good fuel flow and pressure from the pump. If you do, something downstream of the pump is clogged. If you don't, the pump or something upstream of it is the problem. That could narrow things down a lot. But, like I say, most of the time another round of cleaning and changing everything seems to be the answer. Measuring fuel flow and pressure isn't super easy so far as I can tell - you can see if you have any at all, but seeing that you have the right amount requires a way to measure pressure.
 
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mikeyt

New member

Equipment
L2501
Apr 25, 2023
12
10
3
NC
Pulled hose from fuel tank and still have great flow.
Removed filter housing and blew air through. Back together and have great flow.

We shall see but I did not see any gunk come out.

Will do the lift pump test if it starts to sputter again.

Anything special to know about changing the pump? Shaft alignment, removal etc?

Thanks
 

mikeyt

New member

Equipment
L2501
Apr 25, 2023
12
10
3
NC
Still fighting this issue.
Going in th shop next week.
Will report what they find
 
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Mak65

Active member

Equipment
L2501 HST
Apr 25, 2019
122
90
28
TX
Glad to hear she’s running for you again.
 
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TECH101

Member

Equipment
Kubota - Bobcat - Caterpillar - Case - John Deere - FARM - CONSTRUCTION -
Mar 8, 2022
69
15
8
Canada
I would go buy a bottle of Powerservice Diesel Kleen Grey diesel fuel additive and a bottle of Seafoam, add it to the tank, and run it. You likely still have some goo in the system. The Powerservice with added cetane and the other additives along with the Seafoam will help clean it out. Neither will hurt the fuel system, fuel pump, or injectors.

Fuel pumps don't run intermittently on their own, but the pressure could fluctuate with goo in the system or partially clogging the filter.

Then, from now on, use an additive like PowerService Diesel Kleen either Summer or Winter formula from now on. It only takes a bit to keep the fuel from developing algae/bio growth.

I have been a technician for 18 years and currently work for a dealer

I would not recommend any additives (sea foam)

Only diesel conditioner for the winter to pervent gelling
 
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jimh406

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Equipment
Kubota L2501 with R4 tires
Jan 29, 2021
2,356
1,781
113
Western MT
I have been a technician for 18 years and currently work for a dealer
If you are like mechanics at other dealers, you probably only recommend what Kubota tells you to. That's not all bad but isn't the only possible solution. There is a reason why forums like this one exist.

Do you have a solution that costs about the same as Diesel Kleen and Sea-Foam, or what would you have the OP do?