Operator presence issues?

BoB F

New member

Equipment
B7800
Nov 19, 2020
13
0
1
Dunstable MA
I recently purchased a B7800. Once I got it home in the driveway, I began going over all the linkages and lubricating, etc. Afterwards, I found I couldn't start the machine... I could hear a clicking of a solenoid underneath, but no starter engagement. So, I began checking the seat switches, checking on the levers to be SURE they were all in neutral/off position, checked the foot pedal position, and was stepping on the clutch pedal too, but still nothing. So, I tried hot wiring it just so I could move it, but apparently this safety system is connected to the fuel system as well as the electrical since I could get the starter spinning with a jumper wire, but no start. So, I kept fiddling with the levers thinking it might be a sticking plunger switch or something (and it may have been). Well after a day or so, I went to show my son the 'issue', and it started right up and was fine for several days. Just now, after operating for an hour or so, as I left the cab, it quit very suddenly--like I'd shut off the key. Now it's "dead" again even though I didn't move any levers as I left the cab... it just quit. So, possibly it's a defective (intermittent) seat switch, but not sure. Have any of you guys experienced this sort of issue? Or, do you have some 'thoughts' that I am missing here? Thanks for your help, in advance! BoB.
 

orange crusher

Well-known member

Equipment
BX 2680
Sep 30, 2017
356
480
63
ontario canada
First thing I did when I got mine was to by pass the seat switch with a jumper wire. 3 years of no aggravation or problems. That switch was developed by the Kubota Legal Department. It now believes that my fat arse is always on it..........
 

BobInSD

Active member

Equipment
L5740
Jun 23, 2020
361
123
43
South Dakota
The seat switch caused me some issues also. I had a leaky valve stem and was trying to park it with the valve stem up high until the next day. Every time I leaned over to look at the valve stem the thing almost died. I was very frustrated with my "new" tractor until I got that figured out. Suffice it to say that my sixty year old tractors don't do that.
 

BoB F

New member

Equipment
B7800
Nov 19, 2020
13
0
1
Dunstable MA
Hi BobInSD... so, when you lifted a bit, she seemed to "shut off" like with the key switch? If so, what allows you to leave the tractor... setting the parking brake, or placing the drive lever unit in a neutral position? I had been in and out of that cab 25 times or more prior to this instance of getting out and the tractor suddenly shutting down, and it worked fine... I just set the brake.
 

BoB F

New member

Equipment
B7800
Nov 19, 2020
13
0
1
Dunstable MA
First thing I did when I got mine was to by pass the seat switch with a jumper wire. 3 years of no aggravation or problems. That switch was developed by the Kubota Legal Department. It now believes that my fat arse is always on it..........
Hi "Crusher"... my seat has TWO switches... one for when it's raised, and another for when I am sitting on it... which one did you jump by?
 

orange crusher

Well-known member

Equipment
BX 2680
Sep 30, 2017
356
480
63
ontario canada
Hi "Crusher"... my seat has TWO switches... one for when it's raised, and another for when I am sitting on it... which one did you jump by?

My BX only has one coming out of the seat bottom. Try jumping them out one at a time. If it is still doing it try jumping both out at the same time.
 

BobInSD

Active member

Equipment
L5740
Jun 23, 2020
361
123
43
South Dakota
Hi BobInSD... so, when you lifted a bit, she seemed to "shut off" like with the key switch? If so, what allows you to leave the tractor... setting the parking brake, or placing the drive lever unit in a neutral position? I had been in and out of that cab 25 times or more prior to this instance of getting out and the tractor suddenly shutting down, and it worked fine... I just set the brake.
It was in gear, and must be tied to the HST pedal. So long as i didn't touch the pedal it was fine. I did (later) look in the manual, it it is an intentional feature. I'm ok with that, until it breaks, but it drove home the fact that this is more like a giant lawnmower than my older tractors.

I suspect there's some adjustment to center up the HST pedal. Maybe yours is off balance enough that it occasionally thinks you're pushing the pedal? I'm a serious newbie w/Kubota, that's a uninformed guess.
 

Henro

Well-known member

Equipment
B2910, BX2200, KX41-2V mini Ex., Beer fridge
May 24, 2019
5,781
2,965
113
North of Pittsburgh PA
Hi "Crusher"... my seat has TWO switches... one for when it's raised, and another for when I am sitting on it... which one did you jump by?
Just a thought, but with the key in the start position, try moving all the levers that might affect the start, like the direction pedal, pto lever and so on. Perhaps this will give you a hint as to which function switch is the issue...
 

swpflipper

Active member

Equipment
MX5400 HST, LA1065 FEL, HR2572 box blade - S30 flip Screen
Nov 3, 2020
100
53
28
Arizona
I had just under 3 hours on mine and I had a no crank/no start. I held the key in the crank position and bounced in the seat and it started.
It has done this twice. I have not narrowed it down. I am sure the seat switch is the culprit. I thought I read it is only supposed to be dead if the PTO is engaged.
I now have 5 hours on it.
 

retired farmer

Active member

Equipment
tractor, loader, cutter, blade
May 25, 2020
173
90
28
sheridan
I had just under 3 hours on mine and I had a no crank/no start. I held the key in the crank position and bounced in the seat and it started.
It has done this twice. I have not narrowed it down. I am sure the seat switch is the culprit. I thought I read it is only supposed to be dead if the PTO is engaged.
I now have 5 hours on it.
When my L3301 hst was delivered this past summer, the seat switch under the seat was strapped down with a plastic tie. I assume the dealer or someone who works there did that so they could move the tractor about from standing on the ground or something like so. I have found it to be very useful to stand on the ground and use the foot pedal to move the tractor increments for hook ups and such, making sure I am in the clear of course. I am very tall and reach way over so it may not be for everyone but for me it works.
 

random

Well-known member

Equipment
L3301, bucket, backhoe, grader, plow, harrow, cultivator
Nov 2, 2020
717
401
63
NC
On my 3301 there are 3 switches that all work together. PTO, seat (operator presence) and HST. I recently had problems getting it to start. I messed with the PTO and seat switches with no luck, until I learned (from here) about the HST. I tried jiggling the foot pedal while cranking, and it started right up. Maybe that can help?

I've seen it already mentioned a couple times since I posted it not long ago...
 

swpflipper

Active member

Equipment
MX5400 HST, LA1065 FEL, HR2572 box blade - S30 flip Screen
Nov 3, 2020
100
53
28
Arizona
Today it did it again and because of what "Random" wrote, I paid attention and my foot was touching the treadle pedal. Moved my foot and off it went. So then I duplicated it. So looks like it was the nut behind the wheel.
 
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random

Well-known member

Equipment
L3301, bucket, backhoe, grader, plow, harrow, cultivator
Nov 2, 2020
717
401
63
NC
Happy to help!
In my case, the sensor (or whatever) in the switch was stuck and I didn't know about this trick - it cost me a rather expensive trip to the dealer to learn the trick.
 

Henro

Well-known member

Equipment
B2910, BX2200, KX41-2V mini Ex., Beer fridge
May 24, 2019
5,781
2,965
113
North of Pittsburgh PA
Happy to help!
In my case, the sensor (or whatever) in the switch was stuck and I didn't know about this trick - it cost me a rather expensive trip to the dealer to learn the trick.
Random solves a random problem! Does not get better than this! :)
 

digger62

New member

Equipment
B2601
Jan 8, 2017
3
0
1
NW PA
I recently purchased a B7800. Once I got it home in the driveway, I began going over all the linkages and lubricating, etc. Afterwards, I found I couldn't start the machine... I could hear a clicking of a solenoid underneath, but no starter engagement. So, I began checking the seat switches, checking on the levers to be SURE they were all in neutral/off position, checked the foot pedal position, and was stepping on the clutch pedal too, but still nothing. So, I tried hot wiring it just so I could move it, but apparently this safety system is connected to the fuel system as well as the electrical since I could get the starter spinning with a jumper wire, but no start. So, I kept fiddling with the levers thinking it might be a sticking plunger switch or something (and it may have been). Well after a day or so, I went to show my son the 'issue', and it started right up and was fine for several days. Just now, after operating for an hour or so, as I left the cab, it quit very suddenly--like I'd shut off the key. Now it's "dead" again even though I didn't move any levers as I left the cab... it just quit. So, possibly it's a defective (intermittent) seat switch, but not sure. Have any of you guys experienced this sort of issue? Or, do you have some 'thoughts' that I am missing here? Thanks for your help, in advance! BoB.
Had a similar problem with my uncles B7800, tried all the mentioned switches along with a fuel shutoff solenoid and ignition switch. Finally found that there is a controller located in the dash that regulates the fuel system that would periodically malfunction. It would start run then just quit, no pattern. the part number from Messicks is K3511-55222. About $130+. It is sealed so we could not tear it apart to see what failed. Been over a year with no issue.