Mixture always too rich- weber 44 idf's Options

[tornik550]

I have dual weber 44 idf's on my 2258. I was having a problem with one of my cylinders and found that the main circuit had some sort of black booger plugging most of the main circuit of cyl 2 and a small on in cyl 3. I completely cleaned everything and reassembled. The car is driving way better. I set the floats at 11.5 without the gasket.

Now I am having the other problem- my car is always too rich. At idle my a/f ratio is 13:1 which is ok for me. If I try to lean it out any more then I get popping on decel at low rpm's. On the main circuit, I am using 125 mains, f11 et, 210 ac and I am consistently around 10.2:1.

I can but smaller mains but it seems like I shouldn't need that small of mains.

My setup-

idles-50
mains-125
et-f11
ac- 210
vents- 34

Any ideas of how to lean the main circuit?

[jmill]

Initial jetting is always a SWAG and each engine is unique. My gut would say 140-150 mains but I would also never think you'd be at 10-1 with 125's and 34 vents.

I've had 2 sets of Weber 44's with 36 vents on 2 different engines (both 1914 cc's). Main jetting ranged from 135 to 165. 135's with 220 AC jets for the daily driver (Kombi Bus) and 165's with 190 AC jets on my 8,000 RPM drag bug.

I initially had lean transition problems with both of them. Almost lost an eyebrow from a lean pop on the bug. I stepped up to the 55 idle jet and F7 ET and never looked back. Love that ET.

In another thread Racer Chris mentioned increasing the AC jet size to bring the main jet in sooner which would help with lean transition. I've never tried it, it messes with my understanding of the AC jet somewhat but in theory might work. (Purely speculation here since trying to wrap my head around it) A larger AC jet (less restricted) should make it easier for a lower vacuum signal to pull air through the jet stack resulting in flow through the mains sooner.

My understanding was that the AC size didn't come into play until that size started to restrict airflow (higher RPM with more air volume travelling through AC jet). Small sizes restricted sooner, enrichening mixture and larger sizes restricted later giving you a leaner mixture.