Kubota RTV900 issues

treeperch

New member

Equipment
Kubota RTV900
Sep 12, 2023
4
1
1
Stevens Point, WI
I have a Kubota RTV900 that I am having issues with......it will start up, run about 10-15 seconds then die......turn the key off and wait a few minutes, and the same thing happens. I have gone through all the steps listed to bleed and prime the pump even though I did not run out of fuel....so I cracked the lines on the injector pump and watched fuel pump out as I crank it, so I am not convinced that it is a fuel injector issue......is there a relay that could be causing this? What is the starter timer relay that people have mentioned and what does it do?
 

Russell King

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L185F, Modern Ag Competitor 4’ shredder, Rhino tiller, rear dirt scoop
Jun 17, 2012
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Austin, Texas
Some Kubota equipment has a fuel shut off solenoid that is used to pull the injection pump into the off position. Others hold it into a run position. There is some signal sent from the computer telling the machine what to do.

There is some timer involved in that system.

It sounds like the solenoid is not staying in the run position which is another problem those systems have.

See if you can identify that solenoid and see if it moves one direction when cranking and starts and the moves in the opposite direction and then the tractor dies from lack of fuel.

I know I have read some threads on hear about troubleshooting the problem you have but didn’t search for them, perhaps you can find them though. Good luck.
 
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TECH101

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Equipment
Kubota - Bobcat - Caterpillar - Case - John Deere - FARM - CONSTRUCTION -
Mar 8, 2022
69
15
8
Canada
When you turn the key to the ON position you should hear a click if you do not hear it locate the fuel sol
 

lugbolt

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Equipment
ZG127S-54
Oct 15, 2015
5,246
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Mid, South, USA
most of the early 900's you had no click when you turn the key on as the solenoid requires power to turn the engine off as opposed to the X900's, 1120's, etc which required power to turn the fuel ON. The old ones worked backwards, sort of. The solenoid would sometimes stick and cause issues. Those ones is mounted on the top of the injector pump.

what the OP is describing is almost a classic symptom of fuel starvation or contaminated fuel. You can do a free flow fuel test by pulling the line off of the injection pump and putting the end of the line in a jar and then having someone crank the engine over.

it's entirely possible that there is some junk in the tank. Blowing the line out back to the tank displaces it from the pickup temporarily, but can be pulled right back to it in short order. Have run into this a bunch of times on different types of equipment-including the RTV 900.
 
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treeperch

New member

Equipment
Kubota RTV900
Sep 12, 2023
4
1
1
Stevens Point, WI
Ok - I just got this thing back from my brother-in-law who said he could fix it and got nowhere with it, so I am going to start over looking at it myself this week when i get time......does anyone know what the relays in the attached picture do? I cannot seem to locate a wiring diagram for it.
 

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treeperch

New member

Equipment
Kubota RTV900
Sep 12, 2023
4
1
1
Stevens Point, WI
Some Kubota equipment has a fuel shut off solenoid that is used to pull the injection pump into the off position. Others hold it into a run position. There is some signal sent from the computer telling the machine what to do.

There is some timer involved in that system.

It sounds like the solenoid is not staying in the run position which is another problem those systems have.

See if you can identify that solenoid and see if it moves one direction when cranking and starts and the moves in the opposite direction and then the tractor dies from lack of fuel.

I know I have read some threads on hear about troubleshooting the problem you have but didn’t search for them, perhaps you can find them though. Good luck.
How do I know which one my unit has? Fuel on or Fuel off?
 

whitetiger

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Staff member

Equipment
Kubota tech..BX2370, RCK60, B7100HST, RTV900 w plow, Ford 1100 FWA
Nov 20, 2011
2,938
1,398
113
Kansas City, KS
How do I know which one my unit has? Fuel on or Fuel off?
The RTV900 uses the shut-off that is only energized for a few seconds after you turn off the key switch.
A simple test for this style is to unplug the shut-off solenoid which is mounted above the injection pump. If it starts and dies with the white wire unplugged, your problem is not electrical. If it starts and stays running, it's electrical.

When you bleed the fuel injector lines, do not loosen them on the injection pump, loosen them at the injector on the cylinder head.
 

G.rid

Member

Equipment
L48 tlb, ssqa forks, manual thumb for hoe
Aug 19, 2016
207
17
18
Oxford, NS, Canada
From left field....... we had a similar issue with a zoom boom at work. I went through the same troubleshooting thinking it was fuel related.
Long story short, it was parked on a slightly slope and was a little low on oil. The safety switch was submerged in oil to allow it to start but as soon as it started, oil was pumped away from the switch. Therefore the switch commanded the engine to shut down.
Added 1/2 liter of oil and it ran like a top.

Good luck
 
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Longjohnsilver

New member

Equipment
RTV 900
Nov 5, 2024
1
0
1
16102
Fuel problem on my RTV 900 Diesel...I was low on fuel, (gauge read under 1/2), while I was riding in my woods. The machine quit on a steep upgrade, but restarted when I leveled it out. I turned back toward home and it kept quitting on me in shorter and shorter distances., probably 25 times in a mile, but would restart for another short distance. I figured it was out of fuel, so I parked it and walked home. Went and got 1 1/2 gallon of diesel and carried it back to the machine. It started, but continued the same start/stop operation. I now thought "fuel filter clogged." I nursed it all the way home, and looked for the fuel filter. It is inline and buried behind the tank, almost impossible to get to, so I cut out the partition under the seat so I could get to it. I realized that the inline filter is higher than the bottom of the fuel tank by a good 2 or 3 inches, telling me that gravity won't let the fuel flow uphill!..So, rather than remove the filter, I topped off the fuel tank, and it started right up and ran good. I now know, as my Dad always said, " it doesn't cost any more to keep the top half full, as it does to keep the bottom half full. Hope this helps others....
 

whitetiger

Moderator
Staff member

Equipment
Kubota tech..BX2370, RCK60, B7100HST, RTV900 w plow, Ford 1100 FWA
Nov 20, 2011
2,938
1,398
113
Kansas City, KS
Fuel problem on my RTV 900 Diesel...I was low on fuel, (gauge read under 1/2), while I was riding in my woods. The machine quit on a steep upgrade, but restarted when I leveled it out. I turned back toward home and it kept quitting on me in shorter and shorter distances., probably 25 times in a mile, but would restart for another short distance. I figured it was out of fuel, so I parked it and walked home. Went and got 1 1/2 gallon of diesel and carried it back to the machine. It started, but continued the same start/stop operation. I now thought "fuel filter clogged." I nursed it all the way home, and looked for the fuel filter. It is inline and buried behind the tank, almost impossible to get to, so I cut out the partition under the seat so I could get to it. I realized that the inline filter is higher than the bottom of the fuel tank by a good 2 or 3 inches, telling me that gravity won't let the fuel flow uphill!..So, rather than remove the filter, I topped off the fuel tank, and it started right up and ran good. I now know, as my Dad always said, " it doesn't cost any more to keep the top half full, as it does to keep the bottom half full. Hope this helps others....
Your mechanical fuel lift pump has failed.