Outstanding research and documentation. Highest regards for taking the time and posting. Have 2-1/2 hours on my new L2501 and will definitely put this on my to do list.
Thank you for spending the extra effort to film and share. I’ve read some of the forum posts mocking such an idea but I was nearly certain what your research turned up was indeed the case. Nice job!
40 years ago I worked at a Mercedes dealership. I serviced 240 and 300D sedans. A tune up consisted of valve adjustment, throttle linkage adjustment, rack adjustment, and setting injection pump start of delivery (10° BTDC). It was done with a drip tube on injector delivery valve #1 with valve poppet removed. The pump start of delivery was adjusted radially with slots at the mounting studs - much easier than shims. This pump adjustment was done only once usually at around 100K or after valve job/timing chain work. Before tune up was sluggish, rich/sooty, and low max RPM ****like the L2501****. After the tune up the RPM was restored, soot was eliminated and power was restored, like night and day in performance. Some customers never had their cars serviced and they still went 250K miles just slower, sootier and less torque. For a bit more power the timing (at the vibration damper) was set to 11°. Never any harm done to gain a little more torque/HP. I don't see any difference in what we're doing to the anemic L2501. A motor is a motor. What Kubota did, I think, is they Detuned a proven engine to meet a HP number as opposed to tuning an engine that I did many years ago. The Detuned engine runs just as many hours just less power. I think the 9° BTDC is still in spec for the D1703. The Benz 240/300D ran acceptably anywhere between 3° to 10°, Factory spec was 10° which was ideal. 11° was a bit hotter set up being at just over the high tolerance of the spec. Using fuel with a good cetane number was recommended. Great video!!!
You could remove both shims and replace them with anaerobic sealant, lots of low pressure applications use machined surfaces with a sealing compound. Japanese motorcycles use no gasket between crankcase halves, and they don't leak Something like permatex ultra grey or hondabond. also if you are concerned about a used copper washer, you can anneal them to improve their sealing ability
You state that you can't remove all of the shims from the injection pump because of the machine surfaces. In this video ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Us6QuHrhFns.html the guy is using a gasket maker so he can remove all of the shims. What do you think about using the gasket maker rather than leaving one shim? I appreciate your perspective, so I am just wondering. thanks.
I have a new L2501 with only 10 hours when I discovered your videos on increasing HP and loader lift capacity. I heard in your video that you regretted not having established a base line exhaust temperature reading before you messed with the timing and fuel flow. If you still need this info, I will put my tractor through a steep drive in high gear and let you know what the temp reaches. I just finished installing the EGT probe and meter. Also, do you know if there is info on how to remove the engine cover in the owner's manual or the WSM?
New sub. Good stuff. EGR sensor first to baseline makes most sense (said in yer part 2 vid). Im a new owner of a L3901 and while it has a DPF Im also thinking theres potential in that motor to optimize in a similar way… so starting my research down that powerplant road. Thanks for the great and detailed content…
L3901 will be common rail and ECU controlled. Don't know if anyone has figured out how to access/program those ECU's yet, but in theory should just be as easy as providing a new map/parameters that further advance timing and inject more fuel. My seat of the pants guess is that there's probably another 5-7hp in those motors.
Nice to see someone take on this and to know it is possible for a DIY person. Having just a l3001 or l3301 for 2-3k less sounds great. Warranty aside...
Interesting to see the final results. I have a brand new L2501 also. Would be cool to have close to a 3301 HP in a mechanical engine again. On top of the shim job to the loader to increase lift.
WOW. Did you get a 10% or more increase? A lot of work.... I have a B3200 which has the 4cyl and was the last year before all the restrictions kicked in.
Started watching you for the increase in hydraulic pressure, stayed on because you did such a great job with the explanation and testing. Thank you for your efforts. I don’t know what you do but you would have made for an excellent scientist.
Great video. Thanks for putting it together. Interested in what HP you think you ended up at. Thinking of replacing my L285 with the L2501, especially if I can jack up the HP with with no unplanned harm done. Really great analysis.
Seems like these kubota, kioti, bobcat, and tym 25 horses are all the same or very similar. Are these copies of something like the honda small engine clones?
Don't let Tim the Tool man see vid, the grunting would never stop! Now have you noticed any increase in emissions, both in smoke or soot buildup? An operation best done after warrantee expires. Great job, Cheers.
Hi, I am receiving my new 2022 L2501 in about a week , and interested in what you are doing , but scared of screwing things up. Maybe I should wait until the warranty is up. Is the effort in doing this worth the outcome. ?
I'm looking at doing this to my l2501 and eventually a kx033-4 whenever i get one, hopefully this spring. Did you think about removing both shims and doing a thin coat of anaerobic sealant to the pump? that would get you closer to .45mm, maybe .4mm due to the sealant which would be closer to 4 to 4.5 degrees advance, correct?
I think the gap 'between' the stacked shims counts as .5mm (probably something to do with how the rubber compresses against the rubber on the other shim), so I figure I'm 3 degrees advanced over stock. I considered a sealant there, and may try it in the future, but would want to try and conduct some tests to see how much of a 'shim' the sealant ends up acting as. I actually have another D1703 that came out of a roller that I bought for scrap price. I may pull the pump on that one and test with a dial indicator.
I am appalled! Your knowledge is superb, but the engineering of this "pump" is ridiculous. I, too, am diesel trained, but that was many decades ago and apparently a different era. Timing adjustments were made by just rotating the jerk pump body. Most of the time, by using a dial indicator for lift amt vs crank rotation. I am sure most diesels are done this way now, but sure seems like a kludge to me. Nice work and nice vid. Looking forward to the next one!
I don't think you are crazy! This was a excellant video very good information. You explained and showed Everything you did very clearly. THANK YOU!!! l did not expect the explosion at the end. That was the frosting on the cake! I have the same machine and am experiencing a power loss, have not checked it yet. I think its a fuel restriction problem. Your video is something I will keep on the shelf for now if needed.
I concur the L2501 runs odd. I had one… ran very smokey…. Lots of soot like you said and very oily smelling diesel exhaust…. Like a old Ford 7.3l diesel. And the damn thing was loud too…. Like timing was off. Pretty bad. They let me switch for a L3301 which has DPF but runs much smoother and quiet.
The 26 hp rule doesn’t require after treatment. It requires emission levels. Manufacturers can then choose how to achieve the required level of emissions. For example, the Volvo skid steer has a 4.4 liter engine, detuned, no after treatment. Huge torque. Low fuel usage.
Okay I don’t mean to bust yer chops but there’s just a bit of click bait in your title. I would have appreciated knowing from the beginning that this was just part one. That said, I like your thought process. You did a great job explaining everything. You also thought of things that make sense but had not occurred to me. I like many others will be awaiting the results. Question did I miss if you compared injectors? I have a L4060 and like you went to Messick’s. I’ve compared it to the L4760 as far as parts go. The only difference is the injectors. I recently got the WSM and will be comparing everything you did. Thanks for the food for thought.
@@netmagi After a little digging the best I could find is that Bomag bw120ad-4 uses a 34hp version. But like so many industrial companies you have to go to a dealer to get any information.
I have a 2019 L2501 that I purchased new. I actually am very surprised at the amount of power that it has for a “25” horse engine. Like most people that purchase a 2501, one of the main reasons I chose it was to avoid the DPF issues down the road. After it had about 30 hours on it, it completely stopped smoking which I attributed to engine break in. Now any issue of smoky exhaust is completely nonexistent and fuel usage is approximately 1 gph on my average usage. A larger displacement, slower turning engine usually equals longer engine life versus a smaller displacement higher rpm engine which is another reason I chose the 2501. I understand what you’re trying to accomplish in both part 1 and 2 of this video and it’s cool that you did all the research etc… , it’ll be interesting if you do a part 3 in a year or two expressing if you’re still happy with the modifications and whether you still feel it was worth the effort. I guess I’m one of the fortunate ones because I’m not experiencing some of the issues that others are. Thanks for a good video
Has anyone gone further in depth on these engines? Injectors? On the bx series there are some plunger and other parts changed out on the injection pump. I did this on my tractor and it's been a little better , I just am surprised to see more parts for the bx series than l series
Great videos! Question>>>What do you think about just addressing the fuel issue and not the timing issue. I am wondering if I could skip taking off the manifold, etc and just to the fuel adjustment. Thanks, Gary
Question: Maybe you didn’t have access to a milling machine capable of doing this at the time, but wouldn’t you be able to machine down the contact surface of the injection pump to offset the shim you ended up having to leave in place for a gasket? I saw another video where the fella used RTV sealant in place of the gaskets/shims, but this method becomes an unknown variable for injector timing as it will not create a true surface to surface contact. What are your thoughts? Interesting video. Thanks for posting and walking through the whole process and reason for going through this process. Definitely interested in giving this a try on my L2501.
I had the same thought but I don't have a milling machine or access to one. I do have a mill on my mental wish list though :). I think this is the best was to open up a wider range of timing adjustments and still use the available shim selection from Kubota, but pulling even one shim still nets a nice bump in timing in the meantime.
@@netmagi I just gave this method a try with a milling machine over the weekend and it worked very well. Your video was a very helpful tool throughout the process. Thanks again.
@@nicholaspappas101 No I did not. Just taped over all the ports before milling and gave everything a thorough cleaning before bolting it back into place.
Great video! Watched the whole video. I have been anxiously wating for it. You answered my question about just adjusting the rev limiter screw and how HP would not increase. After you did the work did you have to adjust the rev limiter to get past 2200 rpm? Also curious when you did the work and have you noticed any reliability issues afterwards? Can't wait for the next video. AND YES YOU GOT ME!!! lol
I had already adjusted the rev limiter in the past. Worth it just for the usable traveling speed increase in L and M without shifting if nothing else, even if the horsepower increase is minimal with just the revs. Zero reliability issues thus far. I know I'm getting a bit ahead of myself since part 2 isn't out yet, but it actually 'sounds' better to me, and there's so much less smoke, especially at low revs.
@@netmagi I know I bug you alot, but your a great resource. Is yours the HST? Mine is and would like to adjust the rev limiter. Would you mind making a video on adjusting the rev limiter?
Where did you get the schematics and information to know what height the shim to put? I’m having the same problem with my 1505 and I would like to boost it or get it running more efficiently.
I am not sure i am willing to take this on myself. Looked like mostly basic mechanic skills, and I really would like to make my motor live up to its potential. Have you heard of anyone who tired this and destroyed their machine?
I can't stress enough how important it is to install the EGT probe and reader first. If you do that first, set fuel based on temp under load, and put everything back together correctly, your risk is minimal.
YOU WALK THAT WALK! dude thanks so much!!! i dont like long intros! short, sweet and to the point... but outta respect for your work and time i watched from beginning to end. i do have 2 question, 1) other than removing shim/shims, did you do ANY other mods/tuning before or after on the D1703 engine? 2) do you think a bigger airbox would benefit or mod to the canister? btw to all the haters on OTT, dont forget to change your depends and go wax your tractor lmao!!! sub'd and thumbs up!
1) I set the throttle limit to ~2650rpms 2) No, in my opinion, as long as your filters are clean, the factory box is sufficient. If you wanted to turbo in the future, you'll likely find the limits and need to move more air.
Do you think the different valve angles are required to properly seat at these higher combustion cylinder pressures of the older motor or maybe help prevent carbon build up on the valve seats of the newer dirtier (sootier) new version.
It's a good question. I doubt it though. We'd need a Kubota engineer to weigh in to know for sure, but my guess is either slight tuning of airflow for intended RPM range, or more/less turbulence for better fuel mix with DI.
Advancing the timing will give you detonation. Explosion is happening too soon and trying to drive the piston down as it is coming up. Simular sound to when a person uses a little too much starting fluid on a diesel during a cold start. Also sounds a bit like a gas engine with the timing too advanced and in those we call it ping under a heavy load and also by using fuel with a low octane rating under heavy load.
I wouldn't. Particularly if you advance timing, cylinder pressure increases at lower speeds. Even if that pressure isn't really an issue, the decreased temp will lead to wet stacking if it sits idling.
thanks, that's a fair point and a better way to look at injecting too early, but there is no doubt SOME of the energy lost to increased friction from that stress
Yes, without splitting the cases and swapping out the PTO drive gear, we'll never get the full gains at the PTO. I would estimate 50% of the overall gains to total output will apply to the PTO output.
My l2501 blows Bluish/white smoke all the time seemes to be worse under load it’s hard to see at times it’s faint light has to be just right to see it or run it at night then you can really see it loader arms are covered in suit air filter constantly clogs with suit i can’t get kubota to do anything about it been to two different dealers been through three different kubota customer satisfaction agents and still have gotten no where
Give this a shot. Try doing nothing but the timing first and see if you notice a big difference on your machine smoke-wise. I did, but I'm a sample size of one. Make sure you run it under some load before comparing to remove any 'wet stacking' that might have built up before you mod'd.
it seems to me you want to ruin your kubota with all the calculations you did and stuff yes you might be right but it is totaly diffrent story to make it happend.. soo if you really do want to increase the HP of your tractor just put turbo.. but then again the company which is gona make this need calculations temp readings etc etc but the best thing to do is... ask your dealer if they sell transmisions and engines and buy 50 hp one here in EU our L2501 is 50HP not 25 or just get another tractor .
