B2650HSDC safety shut-off issues

Scott_F · Mar 24, 2018

Has anyone else had trouble with the safety shut-off system in the 2650 (or other Kubota) Last spring I was having issues with my tractor randomly shutting off. It wasn't like a fuel or engine issue, it would just shut off, but I could immediately start it back up again. I gradually learned to quickly let off the hyd pedal when it would start to shut down and I could usually keep it running that way (but it was very frustrating). I finally narrowed it down to the seat switch when I used my tractor for a hayride during which some other (heavier) guys drove the tractor and had no problems, but when I drove it would still randomly cut off (I weigh about 165#). I had the seat switch replaced and it ran fine all last summer. This past winter it shut down a couple times while plowing snow, but I was hoping it was just due to the cold. Today I put the mower on and mowed for about 15 minutes. When I stopped and got off the tractor it shut down as though the pto or hyd pedal was engaged (they're not). Now it won't start at all. Have cycled the transmission and pto levers as well as the hyd pedal - no joy. This is different that the issues last spring, but it still seems related to the safety cut-off. My dealer closes at noon on Saturday, so I guess it will sit until Monday. Any suggestions? (besides "gain some weight")

-Scott

moship · Mar 24, 2018

With the key to start, try to slowly rock the hst pedal and then the PTO lever to see if either need adjustment.

Scott_F · Mar 24, 2018

moship - yes, I tried that with no results. One thing I did notice after my first post - when I turn the key on with weight on the seat I hear a solenoid click somewhere under the cab. Without weight on the seat, I don't hear it when I turn the key on. If I hold the key on and move on and off the seat, the solenoid click cycles with the weight on the seat (with a slight delay). So that makes me think the seat switch is ok, but one of the other switches is stuck.

-s

moship · Mar 24, 2018

Did you look at the switches to see if any of them became dislodged?

Could make a temporary jumper to test each switch or use an ohm meter to make certain each one is changing states.

Scott_F · Mar 25, 2018

I looked *for* them, but I can't find them. I just went out to see what would happen if I tried it again and it started right up. I moved about a foot, shut it off, and it's right back in the same mode - won't start.

Scott_F · Mar 25, 2018

It's gotta be the switch in the hyd pedal. Just went back out and tried rocking the pedal around while holding the key on again. I guess I found a sweet spot because it started. Several more attempts at starting it yielded mixed results depending on the pedal position. Don't know how to get to that switch though. Still under warranty so I guess I'll have them get it next week. Sure is frustrating to spend that much on a tractor to have a $0.75 switch keep it from working...

herringchoker · Mar 25, 2018

I had a similar problem with my B7800 over 8 years ago. The safety switch on the HST pedal had gotten loose so that the plunger from the pedal did not contact the switch. Using info from others here on TBN, I was able to find and fix the problem and I documented it (including pictures) at post # 12 in this thread:

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

Your tractor may not have the same setup, but it may be worth checking. At least you still have warranty. Good luck with it.

Scott_F · Mar 26, 2018

herringchoker - thanks for the thread and the pictures. I just arranged to have my dealer pick up the tractor on Friday (I'm leaving for work travel in a few minutes and won't be back until then). I can just barely see what might be the HST pedal switch on mine, but it's especially difficult with the MMM in place. I think I'll let them handle this one...