The Forestry Forum

General Forestry => Forestry and Logging => Topic started by: Bruno of NH on May 17, 2024, 03:34:31 PM

Title: Need tractor help please
Post by: Bruno of NH on May 17, 2024, 03:34:31 PM
I changed the fuel filter on my Kubota l3240 
It's a cartridge type
The tractor started right up and runs good but when you step on the hydro pedal it stalls right out.
It feels like a fuel issue 
What should I be looking for ?
Thanks in advance 
Title: Re: Need tractor help please
Post by: doc henderson on May 17, 2024, 03:55:44 PM
might be air in a line and not able to operate the injectors.  need to bleed the fuel line to each cylinder maybe.  I have also added air pressure to the tank to help the fuel along, but that was when it would not run.  a chunk of Styrofoam to cover the tank opening with a hole in the center for the air nozzle, to create some + pressure in the tank.  does it rev. like it should?
Title: Re: Need tractor help please
Post by: Bruno of NH on May 17, 2024, 04:35:20 PM
After more thinking 
I think I have a safety switch issue 
Maybe with the seat switch, pto safety or on the HST pedal
I hear a clicking when the pedal is depressed 
Thoughts 
Title: Re: Need tractor help please
Post by: thecfarm on May 17, 2024, 05:38:26 PM
Unless your safety switches are different then mine.
My NH won't even start. Most times won't even turn over.
Will it idle? 
When I change filters on mine, I have to keep the switch on, as if I was starting it. Then I turn the bleeder screw, kinda spits and runs rough and then the air comes out and I am all set, Maybe 30 seconds. 
Wife's NH fuel tank is over the filter so open up the bleeder and then it run out a steady stream!!!!
Title: Re: Need tractor help please
Post by: Resonator on May 17, 2024, 05:46:41 PM
Had dirt get into the pedal mechanism on my MX5800 one time and it acted funny. I cleaned it and it worked great again.
Also had a bee get into my fuel one time and ended up plugging the fuel intake. Again cleaned it out and it worked fine.
Title: Re: Need tractor help please
Post by: Wlmedley on May 17, 2024, 05:54:16 PM
If it seems to run alright without any load on engine and then stalls under load fuel pump is probably starving for fuel.Maybe fuel filter wasn't the problem and you have a obstruction in a line somewhere.There is quite a bit of difference in fuel needed to just run and when loaded up and governor opens up.
Title: Re: Need tractor help please
Post by: PJS on May 17, 2024, 06:39:31 PM
If it's a fuel issue, your Kubota should have one of these somewhere on it to save you bleeding everything. My mx6000 gets hay and stuff stuck under the pedal from time to time and won't start without jiggling the pedal. 

https://youtube.com/shorts/06-koNIdG5k?si=Io1PyDF5RYfJygw7
Title: Re: Need tractor help please
Post by: thecfarm on May 17, 2024, 08:12:40 PM
I wonder if it's getting enough fuel?
I had some trouble one winter. Had a very small hill to go up and it would not go up it. I think I had to let the bowl fill up with fuel and then I could go until the bowl was empty.
Title: Re: Need tractor help please
Post by: doc henderson on May 17, 2024, 08:33:59 PM
did you fill the cartridge and bowl with fuel?
Title: Re: Need tractor help please
Post by: g_man on May 17, 2024, 08:59:48 PM
My L3010, which must be similar to your tractor, has the bleed cock just over the injection pump. Let it idle about 30 seconds with the valve open. Then close it. If you leave it open by mistake it runs irregularly and stalls a lot according to the manual.
Title: Re: Need tractor help please
Post by: barbender on May 17, 2024, 09:59:32 PM
If there is a manual primer on the fuel system, it can often indicate issues on the supply side. For instance, if you have a restriction, usually when you depress the primer it won't spring back. If you have an air leak, it will spring back but won't get firm no matter how much you pump it.
Title: Re: Need tractor help please
Post by: rusticretreater on May 17, 2024, 10:36:01 PM
It sounds to me like low fuel pressure. Did your problems did start after changing the fuel filter?  

Where the fuel line meets the fuel injector pump, there should be a bolt for bleeding the line.  Turn the key to the on position, loosen the bolt a bit and you should have fuel pressure from your pump pushing the fuel out.

If the air has gotten past the injector pump into the injector lines, start the tractor and loosen the injector fuel line capnut to let the fuel pressure push the air out of the line.  The capnut should be something like 17mm.  Start with the longest metal line first.

Title: Re: Need tractor help please
Post by: newoodguy78 on May 17, 2024, 11:46:57 PM
Bruno what was your reason for swapping the fuel filter to begin with? Routine maintenance? or was it acting up prior to changing? Trying pinpoint the problem is all.
Not familiar with that particular model but wondering if there's an electric fuel pump in the system that's gotten a little wimpy on you. Another possibility is sometimes there's a filter/screen in the tank that's part of the fuel shutoff. Typically the tank needs to be drained and the shutoff threads out to access this.
Ran into this on one of mine. Tractor would idle fine put it under load and it just couldn't suck enough fuel to do its thing.
Title: Re: Need tractor help please
Post by: rusticretreater on May 18, 2024, 12:59:46 AM
Doh! I had just realized what is probably the real issue and saw that @newoodguy78 has come up with the same cause.  I have had to deal with this also. There is a microbe that grows in the tank if you have water in your fuel and it makes gunk. 

Kubota, very irritatingly puts the low spot of the fuel tank far away from the filler.  A simple check to do is to simply blow some air back up the fuel line in the tank.  Disconnect the fuel line at the pump or the first fuel filter.  You want a clear line to the tank.  Note the fuel flow.  Blow some air up in there and note the fuel flow.  And you have your answer.

So the cure is to stir everything up inside and then siphon the fuel out as quick as you can.  I used a drill powered siphon thingy.  

Run the fuel through a multiple layers of clean rag into a container to save the fuel.  You should see a bunch of gunk, dirt and other stuff that you will have no idea how it got in the tank.   There are you tube vids of fellas siphoning out gunk.  I think that instead of just siphoning which can leave stuff hanging onto the screen or in the tank, that blasting it backwards with compressed air is more effective. 

Then plug the tank connector and put something in there that gets after the gunk.  You can use simple green, dish soap and water, 2 cups vinegar, 1 cup baking soda,and water for dilution. Let it sit for 30 minutes, agitate with air and let sit another 30 mins.  Drain and wash out with diesel fuel.  Let it dry out, refill with fuel and off you go.
Title: Re: Need tractor help please
Post by: Bruno of NH on May 18, 2024, 12:53:00 PM
Thanks for all the advise
It was the connections to both seat switches the one in the seat cushion and under the seat base.
The tractor is 17 years old when I got it just over 250 hours. It sat outside with the seat up most of that time. The sun broke down the wires at where they enter the connection. They had started to split in half. Some new connections with heat shrink took care of it. The old fuel filter I took out was very dirty. It's running great right now. I have 3 fuel filters on the shelve with other maintenance items for it now.
It's almost June summers half over and I got lots to do. 
Title: Re: Need tractor help please
Post by: Magicman on May 18, 2024, 12:56:14 PM
That is a very good update.  ffcool
Title: Re: Need tractor help please
Post by: thecfarm on May 18, 2024, 03:08:52 PM
Good news!!!!!
Title: Re: Need tractor help please
Post by: newoodguy78 on May 18, 2024, 04:34:59 PM
Glad to hear you got it going. Nice work 
Title: Re: Need tractor help please
Post by: Peter Drouin on May 19, 2024, 05:23:29 AM
:thumbsup: