I don't have nearly the experience JB has but I've read about dozens of disasters on the interweb that were caused by fuel pressure regulators. It's been a while so I don't remember what brand regulator they had or if they mentioned. Several of the people who had problems swore off them completely. The impression I got was that they were potentially dangerous enough not to bother with any of them.
Keith Franck is my Weber god. I would have him tune mine but he's on the opposite side of the country (US) from me. As an indication of his knowledge and expertise, he makes his own series of emulsion tubes, idle jets, and accessories. He can be contacted at his sidedraft groups.io site (
https://vintagetechnologygarage.groups.io/g/sidedraft). All that is to say that I am just a messenger here and I have reason to value his opinion.
He recently posted an interesting post about electric fuel pumps and fuel pressure:
FYI, DBE has been selling the 7psi mechanical fuel pump for about 15 years now. I bought one about that long ago and it works a treat without a fuel pressure regulator. Ignore all the experts and the Weber Tuning Manual because they all are wrong. I don't want you chasing a false lead because it will not solve your problem.
Years ago I brought Ken at DBE up to speed on this situation and advised him not to freak out.
Just do the math of the leverage of the float. The ratio is about 4:1 from the lever arm of the pivot to the valve versus the buoyancy of the float to the pivot. The float has plenty of extra buoyancy to handle that extra fuel pressure.
What is in jeopardy is the lobe on the jackshaft. The 7psi loads the jackshaft to the point it wears out quicker. I've already had to replace the jackshaft once on my Elan.
Just to make my point I installed a 5psi electric fuel pump on my Lotus41 which has a pair of 45 DCOE-152 carburetors.
For the record, I use a Facet cube fuel pump. It's been a while since I checked the pressure it delivers but I think it's something like 3 or 4 psi.
With respect to your fuel dripping issue, he recently had a couple of posts that may have bearing on your issues:
On sidedrafts when the fuel is flowing through the main circuits it is also leaking fuel from around the outside of the air horns. To prevent this you need to use this extremely viscous and sticky polyester sealant to stop that leaking. Do not try to use anything else or whatever it is it will eventually end up clogging up the jets. This stuff stays where you put it period.
Besides the air horns, he recommends using it on idle mixture screws to ensure that they are not the source of an air leak. For the record, I do have it on my idle mixture screws but I have not tried it on my air horns though I will be doing that soon. You can get EZ Turn at Aircraft Spruce (
https://www.aircraftspruce.com/catalog/cspages/ezturnlube.php?clickkey=5414).
Here is the second post concerning fuel dribbling:
If you believe one cylinder is being fed more fuel then the first thing you need to do is peer down the throat and look to see the AV or the accelerator pump nozzle is dribbling in fuel due to siphoning. You need to rev the engine to high rpms up so the main circuit kicks in before you take a look otherwise the siphoning may not get started in the AV.
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