Weber 44 IDF mixture help needed Options

[tornik550]

I am working on getting my idle jets correct. My mains seem ok.

At idle (800 rpm) I am getting a reasonable air fuel ratio (14.8 using innovate a/f gauge). I'm using 50 size idles. If I slightly press and hold the peddle to a steady 1200 to 2000 rpm the a/f goes to 19. The car drives like crap until I reach 2000 rpm when the main jets kick in- at the same time the a/f ratio goes to 14 or so.

What adjustments can I make that will leave idle at the same mixture however rich up the mixture til about 2000 rpms? I thought that was mainly idle just only?

I did try to increase the idle jet size to 55. The idle mixture goes down to 11.8 at 800rpm and is perfect between 1200 to 2000 rpm. Confused- I can either get the idle correct OR the low rpms?

I have followed weber's info on best lean each time I switched jets.

Ideas? What am I missing- i'm sure its something simple.

[toolguy]

The idle jets set the mixture for progression holes and also is a rough setting for the idle mixture screws. . . Idle itself is set by the idle mixture screws. . . which controls how much of the mixture given by the idle jets goes on to the lower side of the butterfly. with the butterfly's closed. .

You want to make sure the butterflys are all the way closed in the idle position. . then balance with the air bleed screws. . if they are open, then the idle mixture screws won't have as much effect. . because you're actually running on the lowest progression hole at idle. .

So go back to the idle jets where is was running good at 1/8 throttle, and open the idle mixture screws to fatten it up at idle. If you can close the idle mixture screws all the way at idle, this generally means the idle jets are too big.

It helps if you look at a picture of the carb idle circuit and progression circuit. .