Carb throat popping at speed, New Problem!!! Options

[LetoAtreides]

Ok, so I know I've posted this before, but I still cant figure it out, and I need to know all of the possible circumstances under which this condition occurs.

One of the throads on my dual carbs is excessively lout at speed. It sounds like pop-pop-pop.

Any ideas?

[LetoAtreides]

Update!

I adjusted the linkage on one side, and immediately, the sound switched sides. So I guess it was just the linkages not pulling the same way. So I've adjusted the linkages and now the sound appears on both sides. My next step is to adjust the mixture. I checked the plugs and they were all black, so I guess I'm running too rich.

Just to be clear, the sound appears both on acceleration, and while cruising. Although I haven't driven it for a while, out of fear that something will get screwed up. However, last time i drove it, it was at full power as far as I could tell.

Things I have done so far (in no particular order):
-Throughly cleaned and air-blasted the component parts of each carb.
-replaced and adjusted all ignition components.
-adjusted valves. (many times)
-timed.
-replaced mixture screws, springs, washers and o-rings. (one screw was bent)
-adjusted float on one of the carbs. (it was overflowing)
-checked for vacuum leaks.
-Synched the idle.

The carbs are DellOrto DRLA 36's