I recently repowered a Cletrac HG with a Kubota 1105 engine out of a Jacobsen mower. I swapped out the hydrostatic flywheel for a flywheel that used the stock Kubota clutch since the tractor has a manual transmission. When driving the crawler tractor down a 40% slope the fuel increases on its own. I rigged up a control lever to the manual shutoff on the IP and if I manually restrict fuel at the IP when going down slope it will idle and run at a normal speed. Based on this I am assuming the governor is somehow increasing fuel flow when on a steep slope. Any thoughts or suggestions on how to rectify this issue would be greatly appreciated.
Kubota d1105t governor issues
- Thread starter Jim Leap
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North Idaho Wolfman
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Wow that is a first, so you're having to kill the engine to keep it from overrevving?
So it sounds like the D1105 (three cylinder) or the V1105 (4 cylinder) doesn't have enough resistance / back compression to keep it from over revving.
So it sounds like the D1105 (three cylinder) or the V1105 (4 cylinder) doesn't have enough resistance / back compression to keep it from over revving.
I had to look it up. It originally had a gasoline engine, correct?
Diesels don't have the engine braking that gassers do. You need a jake brake. Or stay off 40% slopes!
I don't think there's anything wrong with your governor. Can you reduce the idle speed? That might reduce the fuel a little.
Diesels don't have the engine braking that gassers do. You need a jake brake. Or stay off 40% slopes!
I don't think there's anything wrong with your governor. Can you reduce the idle speed? That might reduce the fuel a little.
compression braking is mostly nonexistent on diesels.
When one piston compresses air, once past TDC that compressed air acts like a spring and pushes the piston back down the hole-hence, little engine braking. Two options to solve it (and this is universal among diesels)-a bleed off, which pops open the exhaust valve(s) during engine braking (usually electronically controlled e.g. "jake brake"--also quite loud), or a throttle valve that restricts the amount of air that can get into the engine, creating a vacuum in the intake manifold which helps to kind of "pull" against the pistons during the intake stroke (like a gas burner). Exhaust brakes also work but they also can cause EGT to get out of hand quickly if they're not controlled properly.
I wouldn't think that there is enough weight and gear reduction to cause an issue in this application but maybe I'm wrong? If backing the shutoff valve off slows it, it's not likely a compression braking issue, but rather as you stated somehow it's not cutting fuel off? Is this happening at idle speed or above idle? What is the idle RPM?
When one piston compresses air, once past TDC that compressed air acts like a spring and pushes the piston back down the hole-hence, little engine braking. Two options to solve it (and this is universal among diesels)-a bleed off, which pops open the exhaust valve(s) during engine braking (usually electronically controlled e.g. "jake brake"--also quite loud), or a throttle valve that restricts the amount of air that can get into the engine, creating a vacuum in the intake manifold which helps to kind of "pull" against the pistons during the intake stroke (like a gas burner). Exhaust brakes also work but they also can cause EGT to get out of hand quickly if they're not controlled properly.
I wouldn't think that there is enough weight and gear reduction to cause an issue in this application but maybe I'm wrong? If backing the shutoff valve off slows it, it's not likely a compression braking issue, but rather as you stated somehow it's not cutting fuel off? Is this happening at idle speed or above idle? What is the idle RPM?
This over revving issue happens at idle speed. If I head down slope at idle after I've gone about 20 feet the fuel increases on its own and the tractor starts speeding up. Idle is probably around 800 rpm. You are correct - this is not a compression braking issue whatsoever.
When I override the fuel flow the tractor comes back to idle and slows to normal. It is a fuel issue. The governor controls fuel flow independent of the throttle so that is why I am focused on the governor being the issue. I can't help but wonder about differences in governors between hydrostatic and manual transmission tractors. I am thinking in a hydrostatic application the engine only "drives" the hydraulic pump and there is never the type of reverse push on the engine that you would have in a manual transmission when going down hill. I am trying to find someone who would know if there were different governors based on hydrostatic vs manual transmissions. This engine was originally hydrostatic.
North Idaho Wolfman
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There is no difference in the governor between a hydro or geared engine.
Lugbolt, Nailed it when he says your issue is no engine braking.
You do have an engine braking issue!
Without engine braking, there is nothing to slow the engine down, until you cut the fuel and they it's just causing resistance of the dead cylinders to slow it down.
What's happening is you are mechanically spinning the governor via the crank and gears causing it to fuel the engine more and not less.
There is no simple or easy fix for your issue as that engine was not designed for the use your trying to use it for.
Thank for the responses - much appreciated. Just for clarification I am not "cutting" fuel flow and the cylinders are not "dead" I am simply reducing fuel flow to decrease engine RPM running down slope. I had an interesting problem with this engine when I first installed it in the tractor. It would rev out of control even on level ground once it came up to operating temperature with the throttle set at idle. After extensive searching I found someone that had a similar issue and they fixed it by rotating the barrels in the IP slightly to reduce fuel flow. I did this too and it solved the level ground issue. Then when I tested it on a slope it acted very similar. This is why I am fixated on this being a fuel issue.
Stop it on the down slope. With it chocked in neutral, is the idle speed different than it is level? Try the same with it stopped up slope.
I wonder if the governor and/or springs/linkage are different between the mower and a tractor application? They're certainly different between a generator and a tractor application for sure; and many folks tried to use generator engines on tractors or mowers to find out that the engines aren't "identical", contrary to what the internet says.
physically there isn't much that can cause the rack to be moved other than an external issue (throttle links?) OR perhaps a governor issue. Typically the governor would throw the weights out harder which pulls against a fork, which pulls the arm, which pulls the springs that are attached to the rack pin, that cuts the fuel (in normal operation). The way you're descibing it, it almost sounds as if the rack is being pulled the wrong way (adding fuel rather than taking it away) OR there is an injection pump problem that I don't know about.
physically there isn't much that can cause the rack to be moved other than an external issue (throttle links?) OR perhaps a governor issue. Typically the governor would throw the weights out harder which pulls against a fork, which pulls the arm, which pulls the springs that are attached to the rack pin, that cuts the fuel (in normal operation). The way you're descibing it, it almost sounds as if the rack is being pulled the wrong way (adding fuel rather than taking it away) OR there is an injection pump problem that I don't know about.
Thanks for the info on the governor differences between a generator engine and a tractor engine. I can't help but think the same is true for a hydro vs manual transmission as well and perhaps this is my issue. For some reason when the engine is being "pushed" on the down hill the fuel is being increased. I could see where a generator or hydro engine would never be "pushed". Kubota did use the 1105 in tractors with manual transmissions. Maybe I could do a governor parts # search for a Jacobsen mower and compare that info with the same parts on a 1105 powered Kubota with manual transmission.
Went to the Messick's site and looked at governor and speed control plate parts diagrams for both the 2100d (manual transmission) and 2100hst (hydrostatic transmission) and they appear to be identical. So that at least provides some useful information on potential governor differences between HST and geared transmissions.
North Idaho Wolfman
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Ok this is a big deal!
You have now altered the working conditions of the injection pump, so anything else you do or that is happening is out the door on making a concrete assessment.
I've worked on quite a few of the Jacobsen mowers and they take the same governors as the tractor models.
It is a big deal and I am hoping to find a solution at some point. When I described the initial "revving" issue to our local Kubota dealer shop foreman he had no suggestions other than to check that the rack moved freely and that the governor springs were in place. The engine runs beautifully - starts right up, runs smooth, no smoke, lots of power. The guy who suggested the barrel rotation had the same issue and rebuilt the IP to no avail. Then when he rotated the barrels the problem went away. Not sure what my next step is but rebuilding the IP might be next on the list though I am not sure it would help. I would hate to go to the expense of a rebuild and still have the same issue. Pretty frustrating but I am staying optimistic that there is a solution. Thanks for letting me post on this forum and thanks for your consideration.
North Idaho Wolfman
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Let me see if I can find the Jacobson manual (should have one on archive) and and see what the spring arrangement is.
That's the only other thing that I can think of that might make a difference other than the Injection pump being maladjusted.
Ignore the above.
After searching back, I think your issue is related to something in the injector pump related to this thread https://www.orangetractortalks.com/forums/threads/d1105-idles-out-of-control.38369/post-523857
Yes I agree. It was this thread that nudged me to rotate the IP barrels. That worked for my initial "revving" issue but this down slope dilemma is a whole new challenge though most likely related. Thanks!
North Idaho Wolfman
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I loosened the three "tamper proof" torx bolts that hold the barrels in place (on the top of the injection pump) and rotated them clockwise. There is just a few degrees of adjustment.
Here is a "test" to see if problem is governor/IP... or just not enough engine-backpressure.
While going downhill, throttle at IDLE and over-reving is happening...TURN OFF ENGINE (kill fuel delivery)
While going downhill, throttle at IDLE and over-reving is happening...TURN OFF ENGINE (kill fuel delivery)
- If machine continues to move forward and over-rev.... there is NOTHING that can be done to the engine/IP/governor to change what is happening.
- If machine comes to a stop (or slows waayyyy down).... There is something not right with IP/governor
I attached a linkage to the manual fuel shutoff lever on the IP and adjusted the stop to restrict fuel but not completely shut fuel off at idle. When going downhill and over-revving happens the machine will slow to normal when I pull the fuel shutoff lever. This leads me to believe the over-revving is a governor/IP issue.
