Kubota B3200 Stalls While Bush Hogging and Won't Restart

[Lewellan222]

I was operating a B3200 in fairly heavy brush with a LandPride Rotary Cutter. Sometimes when doing this, the cutter gets bogged down and the tractor starts to stall, so I raise the implement (or quickly disengage the PTO) and everything catches up again. When it does stall out completely (I sometimes am too slow to react), I simply disengage the rear PTO, push the clutch pedal, and restart.

The last time the tractor stalled, however, it would not restart. There is lots of electricity, but the engine won't crank at all. Silence.

When considering my problem, please remember it was PTO "overload" that caused the tractor to stall, and the tractor had NO starting issues prior to this stalling event.

I know, you're thinking SAFETY SWITCHES! So was I, so:

SAFETY SWITCH CHECK
- turn on ignition to give tractor power = dash and headlights work (new battery anyway, but voltmeter says all's well)
- engage rear PTO lever (when not seated), and hear the solenoid click in the engine = works
- engage the underside PTO (when not seated), and hear the solenoid click in the engine = works
- rock the speed selector pedal forward or back (when not seated), solenoid clicks= works
- press the SEAT SAFETY button under the seat (or sit on tractor) and ALL of the above switches disengage (I hear the solenoid "unclick") so the seat safety switch is correctly overriding the other switches (as I understand it)

I check the schematic drawings on the B3200, and as far as I can see, there are only four safety switches on this model (rear PTO lever, underside PTO lever, speed selector pedal, and two under the seat; the second underseat one doesn't depress and I don't now how it works)

QUESTION: IS THERE CLUTCH SAFETY SWITCH? Because I sure don't see one on the tractor or the schematic!

From the above, would you agree my safety switches are operating correctly?

Some things I have done:

- worked ALL the pedals, neutral, brakes, differential lock, speed control, etc while holding the ignition key with no result
- checked fuses = all good
- checked battery = all good
- engaged the PTO and rolled the tractor forward hoping to "reengage the clutch" somehow
- disengaged the PTO and made sure the shaft turns freely
- removed the implement

Things I hope are irrelevant:
- there is still a mow deck under the belly, but locked upwards (PTO is still attached! Oh, could THAT be it?!)
- bucket on front created lots of weight forward (yeah, I am grasping here...)

Anyway, thoughts?

 

[jeff9366]

My last Kubota, a B3300SU, had purely mechanical PTO engagement, but there is still an electrical safety switch. B3200 is very similar.

I expect your PTO safety switch is out of line, or a connection has been pulled off the switch under the tractor.

Gently engage the PTO at low engine RPMs, then throttle up. Engaging or disengaging at moderate or high revs slams the PTO linkage, which tends to loosen the switch.

A load of debris under the mower may also prevent the switch from returning to DISENGAGED position, allowing starting circuit to complete. You need a little slack in the PTO drive train for the PTO to disengage.

 

[PhysAssist]

My last Kubota, a B3300SU, had purely mechanical PTO engagement, but there is still an electrical safety switch. B3200 is very similar.

I expect your PTO safety switch is out of line, or a connection has been pulled off the switch under the tractor.

Gently engage the PTO at low engine RPMs, then throttle up. Engaging or disengaging at moderate or high revs slams the PTO linkage, which tends to loosen the switch.

A load of debris under the mower may also prevent the switch from returning to DISENGAGED position, allowing starting circuit to complete. You need a little slack in the PTO drive train for the PTO to disengage.

Hi Lewellan,

I agree with all the particulars you and Jeff have already covered, but we have also been having starting problems more generally with our B2320, and they are clearly centered on the "Speed Selector Pedal", as sometimes rocking it while holding the ignition in the starting position will get it to start if it doesn't otherwise.

BUT, even that didn't work the other day, and what did work was rocking the SSP a little bit side to side- instead of forward and back.

We ALSO have sometimes have to shift it in and out of the PTO active positions a few times occasionally to get it to start, especially if one of us inadvertently snags the PTO lever on an article of clothing while mounting or [mostly] dismounting the seat.

If you're thinking: "Why doesn't he have the dealer fix that obvious problem?"

We tried that- they supposedly fixed it, but the fix lasted a week or so of daily use before the pedal stopped self-centering again, and the starting problems occurred again, and now we're just waiting to get done using the tractor to dig new drainage trenches and get the first mowing done before we get them to pick it up and try again.

It's really frustrating to be told something is fixed, and have it recur again so quickly- especially when what you're using the tractor for is reasonably critical, and even more so when your reasonably new tractor [2011] won't start when you need it to.

 

[Lewellan222]

My last Kubota, a B3300SU, had purely mechanical PTO engagement, but there is still an electrical safety switch. B3200 is very similar.

I expect your PTO safety switch is out of line, or a connection has been pulled off the switch under the tractor.

Gently engage the PTO at low engine RPMs, then throttle up. Engaging or disengaging at moderate or high revs slams the PTO linkage, which tends to loosen the switch.

A load of debris under the mower may also prevent the switch from returning to DISENGAGED position, allowing starting circuit to complete. You need a little slack in the PTO drive train for the PTO to disengage.

Hi Jeff, and thanks for the reply.

When you say that you think "the PTO safety switch is out of line" are you referring to a DIFFERENT switch other than the two connected to the PTO lever system? I know both of those are working correctly, because I've inspected and tested them and they are disengaging solenoid when the operator is seated, as expected. When I move them to "PTO off" I can hear the solenoid disengaging normally which should allow the tractor to start.

As for engaging the PTO, I always do this at lower RPM, then slowly increase the throttle to the requisite 540.

However, you say " You need a little slack in the PTO drive train for the PTO to disengage" which interests me. I have disengaged everything to the PTO, but do you think there is still some tension in the PTO system inside the transmission case?

 

[Lewellan222]

Hi Lewellan,

I agree with all the particulars you and Jeff have already covered, but we have also been having starting problems more generally with our B2320, and they are clearly centered on the "Speed Selector Pedal", as sometimes rocking it while holding the ignition in the starting position will get it to start if it doesn't otherwise.

BUT, even that didn't work the other day, and what did work was rocking the SSP a little bit side to side- instead of forward and back.

We ALSO have sometimes have to shift it in and out of the PTO active positions a few times occasionally to get it to start, especially if one of us inadvertently snags the PTO lever on an article of clothing while mounting or [mostly] dismounting the seat.

If you're thinking: "Why doesn't he have the dealer fix that obvious problem?"

We tried that- they supposedly fixed it, but the fix lasted a week or so of daily use before the pedal stopped self-centering again, and the starting problems occurred again, and now we're just waiting to get done using the tractor to dig new drainage trenches and get the first mowing done before we get them to pick it up and try again.

It's really frustrating to be told something is fixed, and have it recur again so quickly- especially when what you're using the tractor for is reasonably critical, and even more so when your reasonably new tractor [2011] won't start when you need it to.

Hi PhysAssist, thanks for replying.

Yes, I have read quite a few instances of the Speed Selector Lever jamming up and not returning to neutral. But mine is definitely centering, as I can hear the solenoid disengaging as it settles. Also, I inspected that whole "neutral holder linkage" that sometimes jams up (stopping the SSL from returning to neutral) and it's fine.

 

[jeff9366]

Hi Jeff, and thanks for the reply.

However, you say " You need a little slack in the PTO drive train for the PTO to disengage" which interests me. I have disengaged everything to the PTO, but do you think there is still some tension in the PTO system inside the transmission case?

More likely it is unreleased tension on cutter blades, transmitting tension through the PTO shaft. Tension on the cutter blades from bogging down with debris. ~~~Just one possibility.