So I've got the engine running and now I need to adjust the carbs (Weber IDFs). The Weber website says to start with the idle misture screws 1 turn out from lightly seated. But mine seem to screw in until the spring is completely compressed. Does this sound right?

Are you sure it's completely compressed? The spring will get close but the needle should bottom out first. Measure it without the spring to see how far out it seats. Then measure it with the spring to see if it's holding you up.

I've had that problem, but 1 turn out from seated won't be right anyway. You're going to be tweaking and adjusting those guys a bunch. Did you pull the idle screws to make sure the needle is still intact and unworn?

The needles look new, no wear. After trying it without the spring, I put it back on and it does seat before the spring is completely compressed.

I had that problem on my current set of 40IDFs. I ended up cutting the last 1 or 2 coils off the spring. That allowed it to seat, and there is still tension on the spring when they are balanced.

I thought you wanted to start 2 turns off bottom, not 1.

Zach

1 1/2 turns off seated. once engine is warmed up and running SLOWLY turn in one screw till the engine starts to reduce RPM or changes tune. Then back it off 1/4 turn.

repeat for the other 3 barrels.

if you are less than 1 turn out you are too rich on idle jet. more than 2 turns and you are too lean.

It does somewhat depend on your ET. If your using the F11 stick with Joes advice. If your running the F7 you can run a smaller idle jet due to the richer transition of the ET. After 2 1/2 I still go with a bigger jet.