TheSamba.com :: View topic - Gas Drip at Mounting Flange on 30/31 Solex

Tue Dec 16, 2025 7:32 am

1970 Bug with a rebuilt 30/31 done by other.

I just installed it as the final part to getting her back on the road. Everything went well and drove well. But I noticed that the mounting gasket(s) were wet with gas which led to a small drip coming off the mounting studs.(see picture)
There are 2 gaskets that are installed because of the emissions control bracket.
I do not know if that is correct or not and may have nothing to do with the gas issue.
Do I have a float problem, a gasket problem or something else?
Thanks
AR

Tue Dec 16, 2025 7:39 am

Check the throttle shaft to see if that's the source of the leak.

Tue Dec 16, 2025 8:42 am

No leaks from the throttle shaft

Tue Dec 16, 2025 8:46 am

AR wrote: No leaks from the throttle shaft

Pull the air filter and look down the carb throat with a flashlight and see if you can see anything leaking.

Tue Dec 16, 2025 12:08 pm

1970 VW is exempt from California emissions testing. If mine, I'd remove that emissions control bracket and the throttle positioner part.

Tue Dec 16, 2025 12:44 pm

If you don't find any internal leaks, pull the carb and check both mating surfaces with a straight edge; they both need to be flat.

Tue Dec 16, 2025 3:43 pm

If the carb float bowl is overfilling it will leak down there. 2 probable causes are faulty float shutoff valve in top half of carb, they get gummed up and stick, and or excessive fuel pump pressure.

Tue Dec 16, 2025 3:51 pm

i had a similar looking drip/leak there so i snugged that nut some . a while later i went for a 2 hour drive there n back n see the same thing , so i snugged that nut again thinking it was somehow coming loose . it wasent exactly running right either as it was sucking air in right there making it run lean .

it wasent coming loose , i was pulling the stud out of the carb . at first i added new threads to the carb n JB welded the stud in and it held long enough till i found another carb to rebuild .... may not be your problem . but it fixed mine issue .

have you tried to snugg the carb mounting bolts ?

Tue Dec 16, 2025 3:57 pm

messenger123 wrote: If you don't find any internal leaks, pull the carb and check both mating surfaces with a straight edge; they both need to be flat.

I would do this and ditch the throttle positioner gizmo and plate. It's just more possibilities for leaks like you have.

Tue Dec 16, 2025 5:56 pm

my3bugs wrote: i had a similar looking drip/leak there so i snugged that nut some . a while later i went for a 2 hour drive there n back n see the same thing , so i snugged that nut again thinking it was somehow coming loose .

it wasent coming loose , i was pulling the stud out of the carb .
I had this happen like 40-45 years ago; I used a larger SAE stud and nut (drilled the hole in the manifold a tad).

Tue Dec 16, 2025 8:24 pm

suggets you add this to the fle pump it keeps that pin in and fule pumping

Fri Dec 19, 2025 10:19 pm

Thanks everyone for your comments. I ended up replacing the mounting gaskets and it stop the gas leak. Having the emission control bracket sandwiched between two gaskets does lend to a leak problem.
I am considering removing the emissions like it was suggested to reduce problems down the line. I guess I was trying to keep everything period correct.

Sat Dec 20, 2025 10:53 pm

leaking gaskets there will show a symptom and not a cause. The carburetor shouldn't leak or drip, or otherwise discharge fuel after shutdown. Sometimes they do.. but they're not meant to. Float too high can cause it, or fuel pump PSI too high - or even the often-diagnosed, but usually not the problem, vapor lock related heat forcing fuel past the needle.

Sun Dec 21, 2025 5:09 am

As Robert said above keep an eye on how it's running as there should not be late amounts of liquid gas down there. As said before it could be a float or fuel pressure problem.