TheSamba.com :: View topic - Cut-off Solenoid not plugged into anything?

Tue Oct 14, 2025 5:53 pm

I just recently bought my bus and have been dealing with rough idle and cutting out when coming to a stop. I got to looking and saw that the cut-off solenoid isn't plugged into anything. That said, I am wondering if it is shot and the previous owner just rigged it to run without it. I feel like getting a new carb is going to be my best bet, but where would I plug this into? I'm still learning about how all this works, so apologies in advance!

Tue Oct 14, 2025 6:05 pm

Originally there was a wire that came off the 15 side of the coil and it split into 2 wires. 1 went to the idle cutoff and the 2nd one went to the choke. You can also replace that with a fixed jet. If you have the Muir idiots guide it tells you how or search on here for the right jet to put in there.

Tue Oct 14, 2025 6:13 pm

Bobs67vwagen wrote: Originally there was a wire that came off the 15 side of the coil and it split into 2 wires. 1 went to the idle cutoff and the 2nd one went to the choke. You can also replace that with a fixed jet. If you have the Muir idiots guide it tells you how or search on here for the right jet to put in there.

Perfect. That's a start. Mine is a manual choke, but was thinking of changing to a carb with a 12 volt. If going that route, would I need the choke wire to meet at the cut-off solenoid and go to the 15 from there? Or run them to the 15 separately as it sounds like what you are saying? I have heard that the choke runs to the solenoid and is wired to it along with the wire from the 15.

Tue Oct 14, 2025 6:18 pm

The solenoid should have a screw on the face that you can turn to keep it on. If your bus doesn't "diesel" when you shut it off you can just turn that screw and forget about it.

Your plastic fuel lines are possible failure points fwiw.

Tue Oct 14, 2025 7:00 pm

Since you are running an alternator I’m going to assume your Bus is converted to 12v. You don’t state the year of your bus so I can only guess that yours is not set up for a manual choke. You will want to replace your carburetor with a 30 PICT 1 that will run better than the larger 34 PICT carburetor. Looks like you are running a 009 distributor. If you have an unused terminal on 15 (+) of your coil you could run a separate wire for choke and solenoid. If not you will need to daisy chain a wire to choke then solenoid or vise versa.

Until you connect the solenoid to power you won’t know if it’s functioning or not. Running a wire to the solenoid will solve your stalling and idle issues in the mean time.

Tue Oct 14, 2025 8:33 pm

tasb wrote: Since you are running an alternator I’m going to assume your Bus is converted to 12v. You don’t state the year of your bus so I can only guess that yours is not set up for a manual choke. You will want to replace your carburetor with a 30 PICT 1 that will run better than the larger 34 PICT carburetor. Looks like you are running a 009 distributor. If you have an unused terminal on 15 (+) of your coil you could run a separate wire for choke and solenoid. If not you will need to daisy chain a wire to choke then solenoid or vise versa.

Until you connect the solenoid to power you won’t know if it’s functioning or not. Running a wire to the solenoid will solve your stalling and idle issues in the mean time.

Thanks for the info! It's actually a 1973, so it's a Brazilian split and has a 1500 single port. It does indeed have a 12 volt setup and there does not look to be an unused terminal on the coil. I can work with that, though.

Tue Oct 14, 2025 8:36 pm

BarryL wrote: The solenoid should have a screw on the face that you can turn to keep it on. If your bus doesn't "diesel" when you shut it off you can just turn that screw and forget about it.

Your plastic fuel lines are possible failure points fwiw.

It does not diesel on shut off and I assume the previous owner had it this way for a while. And yes, definitely will be swapping out all the lines. I can see some little air pockets in them and wanted to go with better hoses anyway.

Wed Oct 15, 2025 7:11 am

Any auto parts store should have a female spade adaptor that splits into two male ends. Put that on terminal 15.

Wed Oct 15, 2025 7:51 am

Some cut off or screw in or otherwise jam that solenoid in the open position after it fails. Since your car idles at all, this is likely what happened.

Probably simplest to put in a fixed idle jet and move on to other issues.

That is an unusual carb for most countries. Can you post the marking/model information?

I ask because there have been several styles to the solenoid and the replacement fixed jet would be different. Most online catalogs will not cover your carb model.

Wed Oct 15, 2025 10:06 am

KTPhil wrote: Some cut off or screw in or otherwise jam that solenoid in the open position after it fails. Since your car idles at all, this is likely what happened.

Probably simplest to put in a fixed idle jet and move on to other issues.

That is an unusual carb for most countries. Can you post the marking/model information?

I ask because there have been several styles to the solenoid and the replacement fixed jet would be different. Most online catalogs will not cover your carb model.

I can get a picture this evening, but it is a Brazilian Solex H30 Pict as it is on a 73 Brazilian split 1500cc.

Wed Oct 15, 2025 10:40 am

I also thought the top of that carb looked different than any I had ever seen. Also I have never seen the idle solenoid on that side of the carb.

Wed Oct 15, 2025 10:45 am

Bobs67vwagen wrote: I also thought the top of that carb looked different than any I had ever seen. Also I have never seen the idle solenoid on that side of the carb.

I have only found 1 picture that looks like mine and it is only from one side. Pulled this off Google today. The markings on mine are the same as this one.

Wed Oct 15, 2025 12:52 pm

I’ve come across probably three of these over the years. They are not German made. I don’t recall seeing one with a cut off solenoid. I may even still have one. I’ll try to find my carburetor tub.

Wed Oct 15, 2025 1:54 pm

Maybe they separately sell the correct solenoid, too?
https://www.cbperformance.com/product-p/3340.htm?s...Zk2T7byYbz

Wed Oct 15, 2025 3:37 pm

Turns out I still have three of them! I have had a propensity for collecting oddball stuff. The two on the left are NOS or close to it.

Two of them have jets installed, Solex g 65 and ? 55. The third was empty so very well may have contained a solenoid.

One of the nos had an aluminum tag with: 040 129 027-1 stamped on it.

They are set up for the throttle cable spring on the arm, manual choke, slip on fuel inlet, “power fuel” inlet pipe in the throat. An interesting combination of early and later parts.

Many years ago I experimented with one of these to try and determine what vacuum advance distributor these might have been designed to work with. I don’t remember what my conclusion was.

My guess? The PO purchased this carburetor because it was an inexpensive replacement. It’s not the best application match.

Thu Oct 16, 2025 7:04 am

I ran one of those on a '60 singlecab i had so i could use the choke cable.

It worked fine on a 1600.

Thu Oct 16, 2025 7:37 am

Crafty, do you recall what distributor you were pairing it with?

Thu Oct 16, 2025 9:48 am

tasb wrote: Crafty, do you recall what distributor you were pairing it with?

010,019

Thu Oct 16, 2025 1:51 pm

So no vacuum canister involved and the pairing isn’t as important.

Sorry about the “Crafty”. I typed it correctly and my stupid stupid phone likes to fix it for me but not until AFTER I click submit.