BX 23, sputtering and hard/won't start

[K5lwq]

I would be testing the stop solenoid. It either is not getting power or has failed.

 

[safar]

Ok - a lot of things to update on. Not sure how to interpret this, so a it’s a little long;

Went back and tried starting it, after about 5 seconds of cranking it started up and stayed on (it’s a lot warmer than when I tried in the morning, so not sure if that’s the reason.)

Let it idle for 20 mins and it stayed on - sputtered a bit after 10 mins but went back to normal idle.

Managed to drive it a bit and rev it to full throttle and it was fine. Felt like it might sputter but was fine.

Then, disconnected the fuel shut off solenoid and tried starting it and it started right up in half a second.

Connected the solenoid back and it needed 5-7 seconds of cranking to start.

Still doesn’t turn off with or without the solenoid connected and have to manually lift the lever.

So to testing the solenoid as K5lwq suggests.
Connector voltage; same as battery.

Not sure if the diagram is the same as the solenoid for a bx 23 but there’s only a black and red wire from this solenoid and no white, so I didn’t know how to try step 3 and 4.

I tried the battery positive to the red and battery negative to the black and it causes the switch/ button to pop out and stay out for as long as I have it connected and pops back in when I release the connection.
The instructions say to push it in with your finger, but I can’t seem to - it’s really strong.

 

[K5lwq]

If I am understanding correctly yours must stop the engine by momentarily sending power to the solenoid when you turn the switch to off. Then it should retract and it is ready to run next time. So there is a timer relay that controls that if I am correct. As long as the solenoid is powered it would keep the engine from running.

The one I posted works the other way. It has a pull section of the coil and a hold section. That is why it needs 3 wires. It needs power all the time for the engine to run.

The fact that yours will run with the solenoid unplugged tells me that it is retracting but maybe the relay is firing when it is plugged up some times. Next time it happens check the voltage at the solenoid before you turn the switch off. If it has power you need to find out why.

 

[dodge man]

When I had my BX after I shut it off after a few seconds there was a distinct pop, which was the shut off popping so it was ready to start next time. There must be some kind relay or timer like K5lwq said.

 

[JWR]

When I had my BX after I shut it off after a few seconds there was a distinct pop, which was the shut off popping so it was ready to start next time. There must be some kind relay or timer like K5lwq said.

I have several Kubotas (3 B2150s, one BX2200, others I work on) and all of them provide an audible click shortly after you turn off the engine. I assume it to be a solenoid, sounds like one, but never knew what for.

 

[safar]

Thank you all - i never knew what a fuel shutoff solenoid was until yesterday so I’ll work through this tomorrow and revert.

I think I hear the audible pop a few seconds after shutting off, but that doesn’t explain why the engine still runs.
I bought a new solenoid so will try working on them both tomorrow and also try testing voltage at different times and revert.

Thank you all again - sincerely

 

[TractorTech]

It may be the linkage on the solenoid to shutoff is hanging slightly.
Also, if you don't hear pop or see movement, check the fuse. Looking at the wiring diagram for this model, it looks like they relocated to the fuse area. It is rather large compared to the other fuses and it is a 50A.
Visual and audible diagnostics will be easier than accessing the solenoid wiring itself.

 

[JWR]

Are the fuel shutoff valve and the fuel shutoff solenoid two separate items or one unit? Maybe the valve (rather than the solenoid) is hanging up ? I'd lean toward replacing them and having it over with.

 

[Mudder]

BX tractors are self bleeding. Two things to check. They have a small lift pump, it almost looks like a fuel filter but it’s metal. Make sure it’s clicking when you turn the key on but don’t start. I’d also change both filters even though you said you had flow. They are very small and plug easily and they are also cheap. They also had a problem with the sending unit rusting and plugging things up.

Just had the no click issue, fixed with battery jump on a B7800. Battery showed 12v but maybe insufficient Cold cranking amps. Curious for more info on the “lift pump” mentioned, (the fuel stop solenoid ?)

 

[dodge man]

On a BX there is a small lift pump after the rear most fuel filter that pump fuel to the main injection pump. If you turn the key on but don‘t start the tractor you can hear it clicking. Sometimes the tractor will run without the lift pump working because the main injection pump will still pull fuel but it might not run well.