webers are too rich?

I finally finished the removal/cleaning/reinstallation of the weber carbs on my car. I bought a air flow indicator and balanced the airflow on both sides and then reattached the linkage arms. Here is the problem.

when you accelerate there is no power. It feels like it "bogs down" at about 2K rpm. The car idles very smooth thanks to some turns on the mixture screws. These adjustments were required to prevent the backfiring(lean mixture?) through the carbs.

would the loss of power be from a rich mixture? Will the mixture adjustment screws allow me to fix this. I found a fine line between backfiring/lean and rich with smooth idle. Any help would be greatly appreciated. I have searched the previous posts and not found what I am looking for.

Jamie
71 911T targa