L2501 Modifications

Rdrcr

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L2501 Turbo (Current), B2601 (Sold)
May 7, 2021
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Part 2 (the final part) is out:
Are you planning on any additional tinkering?
Are you planning on keeping it N/A or going Turbo at some point?

I might have something you may wanna try;
84B45617-DF50-45B0-ABD6-07CC0434C7B9.jpeg

…an intake and aftermarket off-road air filter.

My L2501 was struggling to go up my big hill in anything but L gear. I’m pretty impatient, so continuing to use L gear was going to be a chore. I wanted to do something about it. I had read (earlier in this thread) about the factory intake being restrictive so I decided to use some scrap aluminum and make a simple intake. Well, after installing the intake, I can go up my steep hill in M gear…with heavy load. So, there definitely was an improvement, it’s just hard to define the improvement without further testing.

The only negative result of the intake installation is noise. The engine is much louder.
It’s not too bad but, I’m wearing earbuds when I’m operating the tractor. Also, there hasn’t been any significant increase in dirt or film in the intake manifold.

Since you’ve already increased the timing and added fuel, this might be a great modification for your tractor!

I’m definitely going Turbo but, I still need to install and log EGT’s and find a local shop with a PTO dyno.

Mike
 
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NetMagi

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BX25D (sold), L2501HST w/BH77 Backhoe
Dec 30, 2014
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Are you planning on any additional tinkering?
Are you planning on keeping it N/A or going Turbo at some point?

I might have something you may wanna try;
View attachment 71985
…an intake and aftermarket off-road air filter.

My L2501 was struggling to go up my big hill in anything but L gear. I’m pretty impatient, so continuing to use L gear was going to be a chore. I wanted to do something about it. I had read (earlier in this thread) about the factory intake being restrictive so I decided to use some scrap aluminum and make a simple intake. Well, after installing the intake, I can go up my steep hill in M gear…with heavy load. So, there definitely was an improvement, it’s just hard to define the improvement without further testing.

The only negative result of the intake installation is noise. The engine is much louder.
It’s not too bad but, I’m wearing earbuds when I’m operating the tractor. Also, there hasn’t been any significant increase in dirt or film in the intake manifold.

Since you’ve already increased the timing and added fuel, this might be a great modification for your tractor!

I’m definitely going Turbo but, I still need to install and log EGT’s and find a local shop with a PTO dyno.

Mike
When you get the probe in, compare EGT's with the same fuel setting but switch out the intake. Would be curious if it makes a difference. If it does, it would indicate it's flowing more air. I don't plan on turbo'ing at the time. Not discouraging you from doing so, but I'm happy with the power level where it's at now and don't want to add complexity.
 
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Rdrcr

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L2501 Turbo (Current), B2601 (Sold)
May 7, 2021
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When you get the probe in, compare EGT's with the same fuel setting but switch out the intake. Would be curious if it makes a difference. If it does, it would indicate it's flowing more air. I don't plan on turbo'ing at the time. Not discouraging you from doing so, but I'm happy with the power level where it's at now and don't want to add complexity.
Absolutely!
It takes only a couple minutes to switch the intakes.

I’ll test with the stock and custom intakes.

Mike
 

Rdrcr

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L2501 Turbo (Current), B2601 (Sold)
May 7, 2021
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EGT Probe has been installed;

FAEF9B51-3405-4213-A910-B79B902D34E4.jpeg

E3766102-FA63-4F8C-9300-2405E9B27DA8.jpeg

Now I just need some seat time to log EGT’s!

Mike
 
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tractorX

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KUBOTA L2501 DT 5' BOX BLADE 42" FORKS PIRANHA TB 5' BUSH HOG 6' GRADER
Sep 27, 2013
75
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Rock Spring GA.
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Chanceywd

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Kubota L2501DT BH77 VIRNIG URG60-CT
Mar 26, 2021
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One thing about that style thermocouple. It has a braided outer jacket and with some the conductors are braided too. Many have a plastic insulation but it depends on application. It only takes it getting braided style wet or pinched between the 2 conductors and you have a cold junction. that will give you a reading of the temperature at that point, not where the probe is.

Bill
 
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NetMagi

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BX25D (sold), L2501HST w/BH77 Backhoe
Dec 30, 2014
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One thing about that style thermocouple. It has a braided outer jacket and with some the conductors are braided too. Many have a plastic insulation but it depends on application. It only takes it getting braided style wet or pinched between the 2 conductors and you have a cold junction. that will give you a reading of the temperature at that point, not where the probe is.

Bill
Seems plausible, though mine has gotten wet quite a few times and never had an issue. They all seem to have this outer braided shield. What other styles have you seen?
 

Chanceywd

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Kubota L2501DT BH77 VIRNIG URG60-CT
Mar 26, 2021
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Seems plausible, though mine has gotten wet quite a few times and never had an issue. They all seem to have this outer braided shield. What other styles have you seen?
I worked in plastic monofilament industry. We used a lot of j type along with the K. In extrusion the operators would let a TC wire get into the quench water and do what I described as the 2 wires had braided insulation too not thermoplastic.. I would guess yours has the thermoplastic wire insulation. I only mentioned because the potential for someone to buy something that wasn't suited for exposure to weather. I has been a few years since I retired so maybe it isn't even a factor anymore.

One way to check a TC is to put in an ice bath, It should then show around 32F vs checking it just to room temperature.
 

Rdrcr

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L2501 Turbo (Current), B2601 (Sold)
May 7, 2021
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I hope to have an update on EGT’s soon. I have everything connected and have made a couple test runs but, I may have a wiring issue since I continue to get an OL reading on my gauge once I get moving and the EGT’s begin to rise.

I’ll need to go over and check everything again.

Mike
 

Chanceywd

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Kubota L2501DT BH77 VIRNIG URG60-CT
Mar 26, 2021
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I hope to have an update on EGT’s soon. I have everything connected and have made a couple test runs but, I may have a wiring issue since I continue to get an OL reading on my gauge once I get moving and the EGT’s begin to rise.

I’ll need to go over and check everything again.

Mike
Do you get a OL when the thermocouple is unplugged? that would indicate an open connection somewhere. If so maybe an intermittent connection in the end terminal or at the sensing end that opens when heated.
 

Rdrcr

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L2501 Turbo (Current), B2601 (Sold)
May 7, 2021
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Do you get a OL when the thermocouple is unplugged? that would indicate an open connection somewhere. If so maybe an intermittent connection in the end terminal or at the sensing end that opens when heated.
Possibly, but I don’t believe so. Regardless, I’ll double check.

I’m going to calibrate it again and check all the connections.

Mike
 

NetMagi

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BX25D (sold), L2501HST w/BH77 Backhoe
Dec 30, 2014
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Was out blowing 3 inches of snow slush this morning. Was able to load the engine real hard for some long stretches running the rear blower. Couldn't get it over 1150 degrees, and hovered around 950ish most of the time under load. Just driving around on level ground it's 300-500. Drops under 300 at idle. I'm still very happy with this mod. I put my older and nicer 'BK precision" probe reader on the shelf and picked up one of the cheap probe readers the same as I had linked before. I'm just leaving it on there. If it eventually gets too wet and dies I'm not worried. The data I get while under load before it eats it was worth the cost. At $20, it's basically disposable :)
 
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Rdrcr

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L2501 Turbo (Current), B2601 (Sold)
May 7, 2021
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Got everything figured out, calibrated and functioning. I had a simple wiring issue…a Red wire isn’t always positive…Who would have thought?

I did a little EGT logging today and weather looks decent for the weekend, so I’ll have some numbers to share then.

Mike
 

Rdrcr

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L2501 Turbo (Current), B2601 (Sold)
May 7, 2021
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L2501 HST 4WD (LA525 Loader w/ 66” QA Bucket) - ALL STOCK, NO MODIFICATIONS.

Testing EGT’s (40* outside temperature):

Idle = 200-300*

Traveling on flat ground (M) = 300-500*
Loader work (M) = 500-700*
Pulling box blade (M) = 500-700*
Traveling up 20* Slope (M) = 600-738*

Peak EGT = 738*

Mike
 
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NetMagi

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BX25D (sold), L2501HST w/BH77 Backhoe
Dec 30, 2014
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Pennsylvania
L2501 HST 4WD (LA525 Loader w/ 66” QA Bucket) - ALL STOCK, NO MODIFICATIONS.

Testing EGT’s (40* outside temperature):

Idle = 200-300*

Traveling on flat ground (M) = 300-500*
Loader work (M) = 500-700*
Pulling box blade (M) = 500-700*
Traveling up 20* Slope (M) = 600-738*

Peak EGT = 738*

Mike
mid 700's under full load seems to be running pretty 'cool', though I guess it's about what I would expect knowing the changes they made to this engine (reduced fuel and retarding spill timing).

thanks for posting your results
 
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Rdrcr

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L2501 Turbo (Current), B2601 (Sold)
May 7, 2021
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WA
mid 700's under full load seems to be running pretty 'cool', though I guess it's about what I would expect knowing the changes they made to this engine (reduced fuel and retarding spill timing).

thanks for posting your results
You're welcome!
I agree.

All my testing was done with light loads/light engagement.
The hardest load on the tractor during testing was heading up my big hill in M gear.

I'm not at all surprised by the results after seeing your EGT's with the performance modifications that you've made and the EGT's that I have recorded stock. Makes a ton of sense.

I'll be logging the EGT's with the custom intake tomorrow.

Mike
 
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Rdrcr

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L2501 Turbo (Current), B2601 (Sold)
May 7, 2021
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L2501 HST 4WD (LA525 Loader w/ 66” QA Bucket) - CUSTOM AIR INTAKE -

Testing EGT’s (42* outside temperature):

Idle = 200-300*

Traveling on flat ground (M) = 285-500*
Loader work (M) = 500-650*
Pulling box blade (M) = 500-650*
Traveling up 20* Slope (M) = 500-703*

Peak EGT = 703*

All testing thus far has been with very light loads and light engagement.

The custom intake appears to have leaned out the A/F a little bit dropping peak EGT’s around 25-75*.

My L2501 really struggles going up my 20* hill. The lowest temperature I recorded going up the hill with the stock intake was 707* and I have to push the tractor to get it to the top. With the custom intake, I was averaging 610-650* on most trips and the tractor wasn’t laboring whatsoever. I had to unnecessarily push the tractor to get it over 700* with the custom intake, basically going full speed in M gear.

I’ll continue to keep an eye on the EGT’s and will likely swap back between the two intakes if I see some abnormalities in temperatures from what has already been recorded.

Mike
 
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