Hey guys just wondering if anyone knows what would be the best pressure to run to twin 40 DHLA Dellortos from a facet electric fuel pump is, its at 5psi at the moment and was wondering if that was too high?
cheers

Factory pressure is fine, no need for another pump. 5psi is probably borderline.

I am running a facet electric pump, as the only pump, the mechanical pump has been removed and blocked off, just need to know what psi to run, as I thought 5psi might be a bit high, what should I run?

Might need to check the wiki but 2-4.5psi sounds right to me. Wait for a second confirmation though.

Everything okay with the carbs?

Just poppin every now and then, running rich, stalling engine at low revs.

Popping is symptomatic of a lean mix, the stalling could also be a result of this.

They need to be reset and balanced properly. I could have done for you in a matter of minutes if I was close by!

Do you have a manual for them to guide you through mixture settings and balance?

Carburetor fuel pressure should be approximately 3.5 psi for all brands, including Dellorto.

Popping indicates lean jetting
Running rich indicates it needs mixture adjustment

yeh need to get it tuned and balanced properly, I could do it myself if I had a manometer, but not buying one when a DECENT one is more expensive than just getting it done at a reputable tuner... just noticed the fuel pressure the other day and was curious as to what was an ideal pressure. It has an electric pump and just a pressure gauge at the moment, gonna need to get an adjustable fuel reg to bring it down to 3.5 psi... cheers ddgonzal and cyclons8 :)

No manometer is needed. Many, many people synchronize carbs with a length of tubing and listening by ear -- and adjust it accurately too.

5 PSI is good, unless the float bowl overflows -- you'll see it run out. The fuel pressure is not directly related to the jetting, because the fuel bowl is vented to atmosphere. Instead, the fuel bowl *level* sets the baseline. By contrast, with EFI the fuel pressure directly relates to rich/lean setting. So check the fuel bowl level - too high means too rich, and too low results in lean mixtures.

Weber will not warranty that their inlet valves will close at 5spi (but usually they will). Mikuni recommends 2.84 - 4.98 psi. Dellorto DHLA I've heard will run great at 2.5 to 4.4 psi.

A stock A-series pump is high volume and with the correct pressure for carburetors (2.8-3.8 psi). But the original 1970-1973 A12 fuel pump is spec'd at 2.6 psi, so check the pressure with a vacuum gauge. Later A12 is spec'd at 2.8 psi. Always test to ensure it is within specs.

haha I am aware that fuel pressure is not related to jetting or whether its rich or lean, was just a question as I noticed it was a bit high. Also I would rather either buy a manometer or get it done properly than use a bit of pipe in the shed and guess haha
But cheers for the specs man, that is what I was after...