Hello, I'm helping a friend troubleshoot an intermediate problem with his fuel solenoid. It seems to arbitrarily de-energize. We took the dash apart and jiggled wires on the dash and near where they go under the fuel tank. We were unable to find anything definitive. When the solenoid was energized I checked the wire(rd/bk) wire from the key switch to the hot wire on the solenoid and put in a jumper wire from right at the switch to the the plug on the solenoid as a means to troubleshoot . The tractor still stalled out within 15 minutes or so of operating it. I'm having a hard time finding a wiring diagram so that I can properly troubleshoot it. I'd really appreciate any help with this and more so information about the wiring for this circuit.
Kubota B7800 Fuel Solenoid
- Thread starter Miket1961
- Start date
thepumpguysc
Elite Member
Regardless of how u have it jumped.. it HAS TO ground THRU the body..
They are a KNOWN problem so its very possible that it does "break down" after running..
They are a KNOWN problem so its very possible that it does "break down" after running..
TBN Support
TBN Support
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Hi and welcome to the forum!
:welcome:
I'm going to move this thread over to our Kubota section to see if we can find you some answers.
:welcome:
I'm going to move this thread over to our Kubota section to see if we can find you some answers.
LouNY
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Many Kubotas energize the shutdown solenoid to stop,
can you remove the solenoid and run the tractor without it?
Mechanically shutting down and opening the fuel.
can you remove the solenoid and run the tractor without it?
Mechanically shutting down and opening the fuel.
thepumpguysc
Elite Member
Mike, That's because when u remove the "power".. the solenoid is spring loaded to shut the engine down.. the solenoid plunger pushes on a control rack inside the pump..
IF you REMOVE IT, theres nothing to push the control rack to the "shut-off" position..
SO.. IT'LL RUN.. U just cant shut it off w/ the key switch now..
IF you REMOVE IT, theres nothing to push the control rack to the "shut-off" position..
SO.. IT'LL RUN.. U just cant shut it off w/ the key switch now..
LouNY
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A question for you thepumpguysc is the kubota like many others that energize to run that one wire goes to a pull in coil then the other wire goes to a hold in coil.
Our IH Magnums use this method, my little kubota uses power to stop from a timer when the key is turned of.
Looking at the replacements for a b7800 it looks like it has the pin that moves the internal rack to run and a spring to return to stop?
You're right pump guy, I didn't think my response through before I replied. I should of said that I don't believe this model to require power to operate the solenoid to shut it off as the only time we've gotten it to run is when we had power to the solenoid. I was not there the last time it stalled. I need to first check if there is power to the solenoid when it stops running and then check the continuity of the ground wire. If anyone has wiring diagram of this circuit I'd appreciate a copy. Thanks for the continued help !
Blondie70
Bronze Member
A poster above sez it has to ground thru the valve body....if so....why would there be a ground wire ???
Just trying to help out.
Just trying to help out.