911T is Very Rough in Mid-RPM's

[Stinky 911T]

I have a 1971 911T with Zenith carbs. Acceleration is very rough from about 2000 to 4000 RPM (coughing and spitting). Idle is also very rough between 900 and 1200 RPM - idle is smooth above or below that range. Engine is very strong from 4000 RPM up to the red line. I know that there is a procedure for adjusting and balancing these carbs, but can anyone point me in the general direction? Is this likely a problem with the float level, timing, or something else?

Thanks,
Bob

[Joe Bob]

Sounds like a fuel delivery problem. Jets or pressure....