Injection Pump and Governor adjustment on D1105

Island Runner

New member
Can anyone tell me what the 3 screws that are capped off near the injection pump are on my D1105? I have attached a pic for reference. I know they are screws for adjusting the governor/fuel delivery, but what does each one specifically control? How does adjusting one affect the other, or is there no correlation between them. I ask because I have ordered a turbo kit for my RTV X1140 and reading the different install instruction from different designs from different companies to get a handle what I am going to be doing, some say adjust this one and that one and another says adjust this one etc., but none of the instructions tell you why or what to expect. They just say move it 1-2 turns and tighten or make the bolt 0.625" from the nut. I want to know what each specifically does so I know what to expect while tuning this thing. Detailed info and explanations would be appreciated! Thanks!
 

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Island Runner

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I should clarify that I am looking specifically at parts #20, #65, and #120. Each different turbo kit says something different in thier install manuals. I'm sure not all turbo kits are exactly the same but I would expect the tuning process to be similar and from what I read, they are not similar in tuning. I can't see why one would say to do this screw and not the next one, and another says to adjust this one and not the 2 the other mentioned by the other manufacturer. Just trying to understand the cause/effect of adjusting each one. Thanks again!
 

geohorn

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I have the complete WSM for the RTV X900 and X1120…. also the Engine WSM for the series 03 engines. The WSM provides detailed disassembly, reassembly, servicing, and adjustment instructions for everything about these engines…. EXCEPT how to adjust the fuel pump.
A Warning is given that should the pump need servicing …it must be returned to an authorized Kubota Fuel Pump Service facility.
They do not even provide identification for the adjustment screws/covers/etc. The Only adjustment information provided is with regard to placement of shims beneath the pump to control timing.
And a strong Warning that the output of the pump is about 2,000 psi…!!!…. Loosening or working on the system can Inject YOU will hazardous fuel under 2K psi of pressure.
 

Island Runner

New member
For people who see this thread looking for answers, I copied and pasted my findings here from my other thread.

OK, here's the update. Just finished up the turbo installation and fueling adjustments. Also did the HST optimization procedure and adjusted the charge pressure and the high pressure relief.

As for the fueling adjustments I made, and as a reference to my other thread asking what the 3 adjustment screws are and what they do, I will try to explain it here.

Screw #20 = Fuel Rack Limit adjustment - Limits how far the fuel rack can be pushed by the governor under load when the RPM drops. Right now I am at 1 turn out from the factory setting and there is slight smoke under load. May adjust further out as I get more hours on it and get a better feel for it.

Screw #65 = Max Fuel adjustment - This screw limits the max amount of fuel the injection pump will deliver. I have no idea as to where the factory setting was. When I finally got the tamper proff sleeve off, the screw and jam nut were loose. I set the screw to 0.650" from end of screw to copper washer as one set of the instructions states. These instructions say that adjustments are case-by-case and even though the machine is running great right now, I'm sure I will adjust it further out as I go.

Screw #120 = Intermediate Governor Screw. I'm really not sure what this does yet. In one set of instructions it said to back it out 2 1/2 turns so thats what I did.

I also advance the injection timing about 2 degrees by taking out the thinnist shim. I feel I could advance it another 2+ degrees but I was left with only 1 shim, which is the thickest one with no holes so I left it in place.

I adjusted the charge pressure in 1 turn as set of instructions said to turn it in 1 to 2 turns. I went one turn but as of now, I do not have s set of Test Guages so in the future I will turn it in some more when I get guages. I really didn't notice any change in HST performance but for whatever reason, shifting from high to low to reverse is much, much smoother. No more stomping brake and tapping the throttle to get it to shift. It is smooth. Not really sure what made it smoother but I like it.

I also adjusted the high pressure relief and turned it in about 3/4 of a turn. Again, no real noticable difference. Again, when I get some test guages, I will revisit the HST adjustments.

As for the turbo installation, I can say this was a really nice and well thought out kit. It was from turbokits.com and actually went together smoothly. The engine bay does get pretty tight and the hardest part was figuring out how to get the nuts and bolts tightend up on the exhaust manifold, turbine housing to exhuast manifold, and a few other places. It trial and error, tighten down this and loosen it up again to tighten something else. It was a bit frustrating at times but get creative and you can figure out how to get it all tightened down.

As for the fueling and HST adjustments, I took instruction from 3 different kits and did all the adjustments they all stated to do. I believe adjusting everything made a huge difference. The machine runs amazingly well and the difference it quite noticable. Like I said, I will continue to make adjustments as I go and get a better feel for it in a working environment but in the brief testing I did last night, all was perfect and well within the parameters I was expecting. Here are my findings.

EGT's never got above 900 degrees. I was not loading the engine to its full ptotential by any means, but I feel with EGT's that low, I can up the max fueling quite a bit yet.

Water and oil temps never got above 180 degrees. Again, it was 20 degrees outside and I was not loading the machine to it's max and only ran 3 miles in the brief preliminary testing last night.

Boost was running about 5 PSI at full throttle in neutral. On the road, at full throttle I was seeing 9 PSI. Again, this is just the machine driving down the road and not putting a real load on the engine. I am guessing by loading the engine, I will see 12+ PSI but that is specualtion at this point and more tuning/testing will be done.

Here's the best part. THE SOUND! It took about 20 minutes for the turbine to "break in" if that is the correct term. For the first few starts and tests, the turbine would only spool up at about half throttle, at least the the point where you could hear it. At low idle, 1500 RPM, it was not producing any boost which I expected. After about 20 minutes of running the engine and keeping an eye temps and smoke levels etc. the turbo seemed to "loosen up" and was whistling at low idle. Right now, it is making 0.75 - 1.0 PSI of boost at 1500 RPM which is surprising to me. It does sound awesome though. The short open muffler connected to the short downpipe really lets the whistle come through in the exhaust note. It makes me smile just listening to it. At full throttle it sounds like a jet engine. I am no stranger to turbo diesels and even though my F350 is deleted, big turbo, tuned to the max, 5" straight exhaust with no muffler, and making about 700 HP, this little Kubota sounds better! Im chalking this project up as a BIG WIN!
 

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aurthuritis

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Test your boost pressure at operating temp with the transmission in stall. Also at this time read the pyrometer. Is your probe before or after the turbo?
 

aurthuritis

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Also there are real limits that the transmission case can withstand without cracking to i would measure the pressure soon.
 

Island Runner

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aurthuritis, my probe is before the turbo. And what are the actual limits of the transmission case? And what about max EGT's? I've heard anywhere from 1100 degrees to 1500 degrees is max. I know the WSM states that max pressure is 3980 PSI but I honestly don't think I can adjust it any higher without going to a thinner jam nut on the screw. The screw is a cap head allen bolt and I was able to adjust it in 3/4 turn maybe until the cap head of the allen bolt bottomed out on the jam nut. I figured I'd get guages and measure it and if I needed more pressure, I would deal with finding a thinner jam nut then. The charge pressure adjustment has plenty of adjustment left in it. I just didn't go over the 1 turn because even though the one manual said 1 to 2 turns in, I felt safe at 1 turn. What effect does charge pressure play in the whole scheme of things anyway? I guess I just adjsuted it beacuse that what it said to do. I had no real idea of why or what I was expecting to happen and didn't notice any change so I still have no idea what the charge pressure really does.

And for boost testing and stalling the transmission, does this mean to put it in high gear and park it up against a tree or something and give it full throttle? Or will the parking brakes suffice and not be damamged? I can do either. It just seems that for checking high pressure relief the WSM states to put the parking brake on, put it in high, and give it max throttle. Same principal?
 

aurthuritis

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For stall you just need to put it in high 4wd to spread out the stress add some weight if needed and tie it or brake or both. I don't remember what the max case pressure is but it isn't a whole bunch more than the factory charge settings. You can overspeed the input speed of the transmission also...i think if i remember correctly don't exceed 3900 rpm? You are probed in to the hot side of the exhaust. I would be conservative on the boost.
 

Island Runner

New member
Thanks aurthuritis. I will give this a go when I get home from work. My high idle speed is 3650 RPM right now which is 550 more RPM than the way the factory had it setup. I will keep an eye on boost and EGT's tonight. I know the instructions in my kit stated to keep max boost around 8-10 PSI. Is there a reason for this? I would asssume the higher the boost, the higher the EGT but if I can keep a good eye on the EGT's, why would more boost hurt? I was thinking the instructions say to limit boost so guys without EGT guages would not be melting pistons but maybe there is a better reason. Any other tips?
 

aurthuritis

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More fuel equal more boost pressure. Also more egt... you can get up to 3800 rpm without damage to the transmission. Without piston cooling jets you run the risk of piston damage. The charge pump along with the charge pressure valve is the pressure that the case runs at and is what fills the high pressure pump. A higher charge pressure will usually help the felt power of the machine. Charge pressure is also the min pressure that the high pressure pump can leak,so you get a little more power out of the hydrostat. Usually a simple adjustment to the fuel rack and charge pressure is what most need. But not before adjusting the peddle to speed rod and governor control.
 

aurthuritis

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There are points to where more boost is just wasting fuel and making heat unless you can increase the rpm up to the 5000 rpm range. But the transmission rotating valve block will grenade at that rpm.
 

Island Runner

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Thanks again aurthuritis! I'm starting to understand this machine a bit better now. Is there such a thing of too much charge pressure in the HST then? I believe the WSM stated 60-120 PSI if my memory is good. How high is too high for the charge pressure? I guess I will test some things tonight and get some guages ordered. I have done the HST optimization procedure and all seems sorted out there. I can hit 3800 RPM using the hand throttle but my pedal stop is all the way to the floor and it seems I just can't get enough throw from the pedal to hit 3800 RPM. I figured 3650 was close enough and moved on.
 

aurthuritis

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120 psi sounds to high for the charge pressure but i am just guessing. It is listed in the wsm i think. It has been a while since i looked all of this up
 

ggmanning

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I have not touched the idle but I will be checking high idle this weekend. Is the consensus set high idle to roughly 3400 rpm?.....I have the same motor on a genset that turns 3600 continuous? I have turned out the fuel rack limit 2 turns. Definite increase in mid range umph noticeable on hills I next went to ajust the max fuel adjustment and like the previous poster the lock nut was loose by the time I got the tamper cap off. So, that is how I found this thread and proceeded to set my max fuel limit screw to .650"length. In my case I had to go to .540" (or screwed futher out) to get back to where I was in terms of speed and power feel. No smoke even under load. My question is at this point what should I do to adjust to the point of a slight amount of smoke under load or less? I have made no adjustment to the intermediate governer screw. Keep slowly adjusting the fuel rack limit or the max fuel limit screws? I have noticed on instructions for those who are adding turbos that the only screws adjusted are max fuel limit and intermediate governer....nothing to the fuel rack limiter. I have already adjusted the transmission servo arm and throttle linkages....they were woefully poorly done on assembly!
 
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aurthuritis

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If you don't have a turbo then leave the fuel setting where it is and adjust only the rack. Adjust your max rpm to at least 3600 rpm or 3800 is safe also. Then get your peddle and the rest set right to see if you are happy. If you do this and then want to add about 3mph to your top? Get some 26 inch tires.
 

ggmanning

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Appreciate that and was hoping you would respond. Biggest issue I have had is there is no instruction in the service manual for setting the max fuel. I am having to go on feel and speed from previous. I will play with it just a bit to try and dial it in to where it was stock because there is no procedure to follow other that the starting point taken from turbo install instructions where I got the .650" reference. I am assuming from where I am now if I go too far on the max fuel setting I will know it by smoke at full rpm and then back it down some. Might stil be slightly rich there but I definitely don't want to lean.
 

aurthuritis

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You really don't want smoke but just a haze when throttling up is ok but when it catches up just barely lean it under the appearance of smoke.
 
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