Kubota B7800 won't start

[Logan979]

Kubota B7800 won't start, battery fully charged, glow plug light comes on but will not engage starter. suggestions

 

[Thomas]

B7800 been known to have seat safety switch issues.

 

[Mendonsy]

Also check to be sure that the PTO lever is in neutral. If it gets bumped off of the neutral position even a little that will prevent the starter from operating.

 

[Dave M7040]

Your tractor, if it is a HST transmission, has an OPC or Operator Presence Controller which prevents or allows the engine to start and run.

I have attached the WSM info on the OPC system.

Usually, the seat switch or the clutch pedal switch are causing the problem but there are other safety switches.

Do you know how to JUMP a starter. This is a step you need to do with great care as every safety device is bypassed and you can end up with a run-a-way tractor or be run over.

Having someone in the seat with a foot on the brakes is the appropriate safety step.

What jumping the starter accomplishes is to establish if your battery and starter systems are good.

Study the attached photo. You can use the shaft of a screw driver or a short piece of wire to do the jumping. Expect a small spark and the engine to crank instantly.

If the key is ON the engine may start.

Dave M7040

 

[orezok]

I just had to replace the rocker pedal neutral safety switch on my B7800. It would start most times but every once in a while it failed. Its easy to bypass with a piece of wire to test. Just unplug the connector and jumper. It is located in front of the right rear tire.

 

[herringchoker]

I've had the rocker pedal safety switch come loose from its mount, causing a no-start. Post # 12 in this thread shows how I fixed it.

https://www.tractorbynet.com/forums/kubota-owning-operating/153385-kubota-7800-wont-start.html

Good luck finding and fixing what is causing your issue.

 

[JWR]

Your tractor, if it is a HST transmission, has an OPC or Operator Presence Controller which prevents or allows the engine to start and run.

I have attached the WSM info on the OPC system.

Usually, the seat switch or the clutch pedal switch are causing the problem but there are other safety switches.

Do you know how to JUMP a starter. This is a step you need to do with great care as every safety device is bypassed and you can end up with a run-a-way tractor or be run over.

Having someone in the seat with a foot on the brakes is the appropriate safety step.

What jumping the starter accomplishes is to establish if your battery and starter systems are good.

Study the attached photo. You can use the shaft of a screw driver or a short piece of wire to do the jumping. Expect a small spark and the engine to crank instantly.

If the key is ON the engine may start.

Dave M7040

Dave is always the good advisor -- The smaller BX2200 and similar have a fairly common "won't start but click when the key is turned" issue. Other threads advise putting in a relay (kit actually sold by Deere I think) that applies a clean 12v directly to the solenoid using the original solenoid signal as the trigger. That's if you have a chronic nuisance in this area. Bypasses all the safety interlocks that have a sordid history of introducing just enough voltage drop to leave the solenoid unsatisfied. One can confirm that this is the issue by hooking a battery charger to the battery (which supplies slightly more than 12v) and then it starts. Thats IF the problem is lacking voltage to the solenoid and IF you have clicking but no turning using the key. There are of course other issues (like one of my B2150's has a cranky, no pun, starter. I have to tap the starter once in a while in order to start it.)