B2650 doesn’t die when turn key off

[Rene’e]

I have a 2016 Kubota B2650HSD. When you turn the key off it continues running, you have to put hand over breather and shut off air supply. It started doing this and missing at the same time. It’s ran perfectly, not used a whole lot. Replaced the key stop solenoid, checked all fuses and it’s still doing it. Blew air through all the fuel and injector lines as well and it’s still missing. I’m stumped, any suggestions please

 

[North Idaho Wolfman]

You need to follow what the WSM says to do to troubleshoot it.

Does it have a cab or not?

 

[Mark_BX25D]

Replaced the key stop solenoid, checked all fuses and it’s still doing it.

Let's go to the basics. You are getting fuel from somewhere. Now to find out where.

I don't know your particular tractor, but most of the fuel shutoffs need 12v to keep them open so that fuel will flow. Shut off the key, voltage is removed, spring closes the valve. That's how it should work.

So let's answer some basic questions: When it's not shutting off, is there 12v at the solenoid? Have you tried manually actuating the shut off valve? Is there an external spring or is it built into the solenoid? Have you bench tested the solenoid? (Bad out of the box DOES happen sometimes.)

 

[Runs With Scissors]

Before firing off the "parts cannon" again, I also suggest grabbing a copy of the WSM and a multi-meter.

I would also suggest to try and fix/focus on one thing at a time, starting with the "no shut off" problem.

Trying to troubleshoot multiple things at one time has always turned out to be a "fools errand" for me.

 

[biketopia]

Have you bench tested the solenoid? (Bad out of the box DOES happen sometimes.)

Good information. When the guys at work tell me "well it's new, it should of fixed it," I always remind them that the new stands for Never Ever Worked. Always perform diagnostics and verify repair. Also like RWS said, focus on one thing at a time, I'd start with the run on problem.

 

[Dustball]

Let's go to the basics. You are getting fuel from somewhere. Now to find out where.

I don't know your particular tractor, but most of the fuel shutoffs need 12v to keep them open so that fuel will flow. Shut off the key, voltage is removed, spring closes the valve. That's how it should work.

So let's answer some basic questions: When it's not shutting off, is there 12v at the solenoid? Have you tried manually actuating the shut off valve? Is there an external spring or is it built into the solenoid? Have you bench tested the solenoid? (Bad out of the box DOES happen sometimes.)

On the B2650, nothing is accessible as the solenoid bolts directly to the block.

I'd say the solenoid is working fine as the engine is running. If the solenoid wasn't working, the engine would not be running. I'm thinking its welded shut contacts in the 12V relay supplying the solenoid.

I have a small list of electrical component interchanges determined by reading the manufacturer info on the parts on my tractor. Here's what I have for the B2650 key stop solenoid relay.

 

[Mark_BX25D]

Well, that's a pain!

But I see a connector there that can be probed (a safety pin will get in there easily) to see what voltage is happening, and when.

Good place to start.

 

[Dave_eng]

I have a 2016 Kubota B2650HSD. When you turn the key off it continues running, you have to put hand over breather and shut off air supply. It started doing this and missing at the same time. It’s ran perfectly, not used a whole lot. Replaced the key stop solenoid, checked all fuses and it’s still doing it. Blew air through all the fuel and injector lines as well and it’s still missing. I’m stumped, any suggestions please

I believe your machine has a controller which, when the key is turned to OFF, provides power to the engine stop solenoid for a few seconds to stop the engine. This is the opposite to which other posters are suggesting.

There is also a fuse which I circled in red which needs to be checked.
I have not studied this system for a few years so others may correct me!

Dave

 

[biketopia]

I believe your machine has a controller which, when the key is turned to OFF, provides power to the engine stop solenoid for a few seconds to stop the engine. This is the opposite to which other posters are suggesting.
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There is also a fuse which I circled in red which needs to be checked.
I have not studied this system for a few years so others may correct me!

Dave

Great info you pulled!

 

[Dustball]

I believe your machine has a controller which, when the key is turned to OFF, provides power to the engine stop solenoid for a few seconds to stop the engine. This is the opposite to which other posters are suggesting.


There is also a fuse which I circled in red which needs to be checked.
I have not studied this system for a few years so others may correct me!

Dave

The B2650HSD's key stop solenoid works the opposite of what you're describing.

The solenoid receives power during operation to keep the fuel flowing. Only when voltage is removed from the solenoid is when the fuel stops flowing. I know this for a fact as I bought my tractor from an auction as "non-running" and one of the reasons was because one of the terminals at the 30 amp fuse supplying the key stop solenoid was corroded and broken off which caused no voltage at the solenoid to retract the plunger. No voltage at solenoid = no start/run.

There are sections of the WSM about the stop solenoid that are incorrect describing what you had posted.

This section is correct-

 

[North Idaho Wolfman]

@Dave_eng and @Dustball

Your both right, I bet that bends both your brains...

News flash:
There is two possible versions of the B2650 control system.
One has a run solenoid and one has a stop solenoid.
So you would need the serial number to know which system you have.

 

[Dustball]

@Dave_eng and @Dustball

Your both right, I bet that bends both your brains...

News flash:
There is two possible versions of the B2650 control system.
One has a run solenoid and one has a stop solenoid.
So you would need the serial number to know which system you have.

Thank you for the input.

I suppose it doesn't matter if the OP never comes back to read any of this and follow up. It's a post-once-and-run situation.

 

[North Idaho Wolfman]

Thank you for the input.

I suppose it doesn't matter if the OP never comes back to read any of this and follow up. It's a post-once-and-run situation.

It happens.

 

[Dave_eng]

@Dave_eng and @Dustball

Your both right, I bet that bends both your brains...

News flash:
There is two possible versions of the B2650 control system.
One has a run solenoid and one has a stop solenoid.
So you would need the serial number to know which system you have.

Is it possible that the tractor with the run solenoid (Runs without power to solenoid) is the one which is equipped with OPC (Operator Presence Control). Can machines be sold in North American after a certain year without OPC?

I have been confused in the past using a WSM from Kubota Books and then find out they are the WSM for tractors sold in Scotland. The North American tractor was not covered adequately by the Scottish WSM.

Dave

 

[North Idaho Wolfman]

There is actually quite a few variances to all model that are sold in mutiple countries.
On this model there is a bunch of changes made on US and Non US units and it varies all over the board.