Difference in fuel stop solenoids

[Ursa Minor Beta]

Hello community,
i just noticed that there is a difference between my old D1005 stop solenoid and a newer version.
The old one just had one connection and ground to shut of the fuel rack.
It seems that the newer ones need to be engaged to allow fuel to flow.
They also have two connectors.
Can anyone enlighten me on these? and how to connect them properly?
thanks!

 

[PoTreeBoy]

AFAIK, there are 3 basic Kubota solenoid schemes. Before solenoids, there were mechanical fuel shut-offs, and the newer common rail systems don't need a solenoid.
1. Energize to shutoff. These have one terminal and a shutdown timer that sends power to the solenoid for 5-10 seconds when the key is turned off.
2. Pull-in and hold coil, external switch. These have two terminals. One goes to the more powerful pull-in coil which is energized when the key switch is in 'start'. The other goes to the hold coil which is energized when the key switch is in 'run'.
3. Dual coil, internal switch. This is similar to 2., but the pull-in coil is controlled by a switch inside the solenoid body. It has two terminals, but these are typically jumped together in the wiring harness. When power is applied, both coils are energized until the armature moves in and opens the switch on the pull-in coil.

It sounds like you have 1. Check the terminal voltage. There should be no voltage until you turn the key off. Then there should be 12 volts for 5 to 10 seconds, then 0 volts again. If this doesn't happen, there could be a broken wire or bad timer/relay.

You can test the solenoid by applying 12v to the terminal and grounding the case. The solenoid should pull in.

If you need more help, attach a picture of the solenoid and the fuel shutoff area of your engine. There may be a part number embossed in the solenoid body.

 

[Ursa Minor Beta]

Hello and thanks for the quick and informative reply.
Well I used to have 1 but the new engine is either 2 or 3.
I dont have the original harness and had made my own cables before.
With this solenoid I had just wired one cable to a temporary switch which connects the solenoid to power and thus switch the engine off.
I do prefer that version because if there is any issue with the cable the engine can still start.
The one I have now needs to be engaged to have the engine start.
What is the purpose of the dual coil system? Does it have two positions to have different fuel amounts for start and run?
Thanks again!

 

[PoTreeBoy]

What is the purpose of the dual coil system? Does it have two positions to have different fuel amounts for start and run?
Thanks again!

There are two coils to avoid overheating the solenoid. Pulling in the armature requires several times the current as just holding it in. If the pull-in coil is continuously powered, it would burn out.

 

[PoTreeBoy]

Hello and thanks for the quick and informative reply.
Well I used to have 1 but the new engine is either 2 or 3.
I dont have the original harness and had made my own cables before.
With this solenoid I had just wired one cable to a temporary switch which connects the solenoid to power and thus switch the engine off.
I do prefer that version because if there is any issue with the cable the engine can still start.
The one I have now needs to be engaged to have the engine start.

Can you install the old solenoid on the new engine? If you can attach some pictures it might help. As you've discovered, the same model engine can have different systems.

BTW, many of the tractors with the energize to shutoff system, like my L35, have a manual knob and cable to kill the engine in case the electrical part fails.

 

[Ursa Minor Beta]

Ah. I see. So there is no easy way in wiring this up. Needs a timer ( capacitor driven relay ) then?
Unfortunately I only have the wiring diagram for the old setup.

 

[Ursa Minor Beta]

Can you install the old solenoid on the new engine? If you can attach some pictures it might help. As you've discovered, the same model engine can have different systems.

BTW, many of the tractors with the energize to shutoff system, like my L35, have a manual knob and cable to kill the engine in case the electrical part fails.

The attached image is of the current solenoid.
Unfortunately the old one was very corroded and not working anymore.
Don't have an image of that. But it did not have the denso style connector but rather a sort of t-shaped white connector with two standard 6 mm flat terminals
I guess it was this one:

https://www.tracpartz.com/p/kubota-stop-solenoid-kx41-2-kx61-2-kx91-2-r310b-bx2200-bx23-f2400-fz2100-d1105/

 

[PoTreeBoy]

Ah. I see. So there is no easy way in wiring this up. Needs a timer ( capacitor driven relay ) then?
Unfortunately I only have the wiring diagram for the old setup.

If I interpret your post #3 correctly, you just replaced the timer with your manual switch (momentary close, I assume). This works as long as you don't leave power on longer than necessary.

If you want to keep this setup you'll need to use the older solenoid. My tractor, which uses a D1703 engine with the single coil solenoid, has an external fuel shutoff arm. Some of the newer, dual-coil solenoids have a pin that goes into the governor to push the rack to shutoff.

 

[Ursa Minor Beta]

Yes. I could just remove the solenoid, close the opening and then install a bowden cable to the mechanical shut off.
But I liked the simple old setup which worked for me for 5 years with the old engine.
Will probs just replace the solenoid.
Thanks for all help here!

 

[North Idaho Wolfman]

If the stop solenoid is on the rear of the engine it should have a single coil and be a stop coil.
It's very easy to add the needed timer to run it if you want it fully automatic.

If the coil is mounted to the front of the engine, then it's a run coil and will have 2 coils, pull in and hold.

Now there are some variations to this, if powering the solenoid Pull the coil in to stop the engine, then The 2 coil version can be used if you only need to temporarily power it to stop the engine.
You simply just power both of the coils at the same time.
It's much easier to add a timer that powers the coil or coils for approximately for 5 second apon shutting the key off.

 

[PoTreeBoy]

There is a Kubota tractor model B2320 which uses a D1005 engine. It may or may not be like yours. There is a WorkShop Manual available at KubotaBooks. You can see parts diagrams on KubotaUSA if you're in the US. It seems to be an entergize to stop system with a 2-wire solenoid controlled by a controller. But I can't tell how it works by the description in the WSM. Have you tried starting your new engine with no power on the solenoid?

It looks like the B2320 has an external stop lever, but I can't tell for sure. You can look at the L35 parts to see how that is set up.