D1703 engine

Yotekiller

Well-known member

Equipment
Kubota L2502, LP 60" BB, LP pallet forks, 60" KK Tiller, 55" HSI root grapple
Sep 29, 2023
332
374
63
Southern Indiana
I have been researching the D1703 engine quite a bit recently. There are many variations of it and some running 2800RPM's at around 35HP. I have seen videos of people removing shims on the injection pump and adding a bit more fuel to it to gain considerable more power. On the 2501 the engine is a D1703 - M and on the 2502 it is D1703BM and I cannot for the life of me determine what the BM/M means. I have also read that the 2502 has a different injection pump than the 2501. I am really wanting to turn the power up on my 2502 ( if for no other reason than because I can't leave any engine alone).

Does anyone have any info on the D1703BM and what the differences are? I would love to hear any experiences you have had turning up the 2501.
 
  • Like
Reactions: 1 user

Yotekiller

Well-known member

Equipment
Kubota L2502, LP 60" BB, LP pallet forks, 60" KK Tiller, 55" HSI root grapple
Sep 29, 2023
332
374
63
Southern Indiana
On the L2501, the pump assy is part # 1G830-51012 and the 2502 it is 1J871-51010. I don't see any differences between the two on the drawings and they have the same PN's for the gaskets as well. I started comparing nozzles, and that entire nozzle assy looks the same but also has different part numbers. There is a $500 difference in price with the 2501 being more expensive. I wonder if this was simply a cost savings decision and went with a cheaper pump from a different manufacturer...
 
Last edited:

North Idaho Wolfman

Moderator
Staff member
Lifetime Member

Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
30,249
6,405
113
Sandpoint, ID
On the L2501, the pump assy is part # 1G830-51012 and the 2502 it is 1J871-51010. I don't see any differences between the two on the drawings and they have the same PN's for the gaskets as well. I started comparing nozzles, and that entire nozzle assy looks the same but also has different part numbers. There is a $500 difference in price with the 2501 being more expensive. I wonder if this was simply a cost savings decision and went with a cheaper pump from a different manufacturer...
Removing or adding shims DOES NOT give it more fuel.
Wherever or from whom ever you have read that from, they are full of it.
The shims adjust timing, not the amount of fuel.
There are other adjustments for the amount delivered each model differs in the method.
 

Yotekiller

Well-known member

Equipment
Kubota L2502, LP 60" BB, LP pallet forks, 60" KK Tiller, 55" HSI root grapple
Sep 29, 2023
332
374
63
Southern Indiana
Removing or adding shims DOES NOT give it more fuel.
Wherever or from whom ever you have read that from, they are full of it.
The shims adjust timing, not the amount of fuel.
There are other adjustments for the amount delivered each model differs in the method.

Either I typed that wrong or, you read it wrong. ;) What I was attempting convey was that I needed to remove shim(s) to advance the timing AND adding a bit more fuel by adjusting the screw...
 
  • Like
Reactions: 1 users

North Idaho Wolfman

Moderator
Staff member
Lifetime Member

Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
30,249
6,405
113
Sandpoint, ID
Yes your right I did miss read it. :(
Sorry.;)
 
  • Like
Reactions: 1 user

Rdrcr

Well-known member
Lifetime Member

Equipment
L2501 w/ S2T Turbo Kit = 35 PTO HP (Current), B2601 (Sold)
May 7, 2021
672
741
93
WA
The injection pumps on the L2501 and L2502 are completely different. I haven’t had the chance to really dig in and research the L2502 pump yet but, if you do a search, I made a thread and took some pictures illustrating the differences between the two tractors.

Mike
 
  • Like
Reactions: 1 user

Yotekiller

Well-known member

Equipment
Kubota L2502, LP 60" BB, LP pallet forks, 60" KK Tiller, 55" HSI root grapple
Sep 29, 2023
332
374
63
Southern Indiana
The injection pumps on the L2501 and L2502 are completely different. I haven’t had the chance to really dig in and research the L2502 pump yet but, if you do a search, I made a thread and took some pictures illustrating the differences between the two tractors.

Mike
I have read that post! I can't find ANY information on that pump. I can pull up the parts diagram for it and compare it to the 2501 pump and everything looks absolutely identical. I would really like to find out what those differences are. I want to pull it off and play with the shims but I am a little worried since I don't know what the differences between in and the 2501 are..
 

Rdrcr

Well-known member
Lifetime Member

Equipment
L2501 w/ S2T Turbo Kit = 35 PTO HP (Current), B2601 (Sold)
May 7, 2021
672
741
93
WA
IMG_8164.jpeg

L2502 Injection Pump

IMG_6305.jpeg

L2501 Injection Pump.

Mike
 

Rdrcr

Well-known member
Lifetime Member

Equipment
L2501 w/ S2T Turbo Kit = 35 PTO HP (Current), B2601 (Sold)
May 7, 2021
672
741
93
WA
I have read that post! I can't find ANY information on that pump. I can pull up the parts diagram for it and compare it to the 2501 pump and everything looks absolutely identical. I would really like to find out what those differences are. I want to pull it off and play with the shims but I am a little worried since I don't know what the differences between in and the 2501 are..
You can’t trust the parts diagram. The L2502 pump is a different design. However, you’re more than welcome to pull it off and play with the shims. Please take pictures if you do.

Mike
 

Yotekiller

Well-known member

Equipment
Kubota L2502, LP 60" BB, LP pallet forks, 60" KK Tiller, 55" HSI root grapple
Sep 29, 2023
332
374
63
Southern Indiana
You can’t trust the parts diagram. The L2502 pump is a different design. However, you’re more than welcome to pull it off and play with the shims. Please take pictures if you do.

Mike

Yeah last night I started looking at mine and compared it to the video of the 2501 pump being shimmed and realized they were completely different. I am contemplating removing it so I can take a peak and also to see if it is a Bosch pump and has a part number on it.

I'm doing nothing that I NEED more power from my 2502 but, I just can't get past the thought that there is most likely HP sitting on the table that's not being tapped into. I just feel the timing needs advanced to make it run where it should be...
 

Rdrcr

Well-known member
Lifetime Member

Equipment
L2501 w/ S2T Turbo Kit = 35 PTO HP (Current), B2601 (Sold)
May 7, 2021
672
741
93
WA
^^^
I’m pretty sure there’s some additional power to be gained by adding fuel and advancing the injection timing (and possibly increasing the RPM limit).

In time, we’ll be developing a Turbo system for the L2502, however, more research needs to be done on the new injection pump and engine internals.

I didn’t necessarily ‘need’ more power out of my L2501 but, the Turbo kit prevented me from ‘thinking’ I needed to upgrade to a new tractor. I’m now more than happy with a dyno proven 44.1HP and 35 PTO HP.

Mike
 
  • Like
Reactions: 1 user

Yotekiller

Well-known member

Equipment
Kubota L2502, LP 60" BB, LP pallet forks, 60" KK Tiller, 55" HSI root grapple
Sep 29, 2023
332
374
63
Southern Indiana
^^^
I’m pretty sure there’s some additional power to be gained by adding fuel and advancing the injection timing (and possibly increasing the RPM limit).

In time, we’ll be developing a Turbo system for the L2502, however, more research needs to be done on the new injection pump and engine internals.

I didn’t necessarily ‘need’ more power out of my L2501 but, the Turbo kit prevented me from ‘thinking’ I needed to upgrade to a new tractor. I’m now more than happy with a dyno proven 44.1HP and 35 PTO HP.

Mike

I searched hard for a L2501 so I could buy and install your turbo but couldn't find one so had to take the 2502 instead. If you come out with it for the 2502, I will be one of the first customers.

I agree, I think there is more power to be had as well. I just can't find any information out there on this engine, not even a WSM can be found.
 
  • Like
Reactions: 1 users

Rdrcr

Well-known member
Lifetime Member

Equipment
L2501 w/ S2T Turbo Kit = 35 PTO HP (Current), B2601 (Sold)
May 7, 2021
672
741
93
WA
^^^^
All you have to do is get your tractor over here and give us 30 days and it’ll have a new Turbo Kit! ;)

We’ll definitely have a Turbo Kit for the L2502. We just need a tractor and a bit more research needs to be done on the injection pump and engine internals as mentioned previously.

Mike
 
  • Like
  • Haha
Reactions: 1 users

Yotekiller

Well-known member

Equipment
Kubota L2502, LP 60" BB, LP pallet forks, 60" KK Tiller, 55" HSI root grapple
Sep 29, 2023
332
374
63
Southern Indiana
^^^^
All you have to do is get your tractor over here and give us 30 days and it’ll have a new Turbo Kit! ;)

We’ll definitely have a Turbo Kit for the L2502. We just need a tractor and a bit more research needs to be done on the injection pump and engine internals as mentioned previously.

Mike

I wish I could get the tractor to you! LOL
 
  • Like
Reactions: 1 user