Weber IDF always rich- Please help! Options

[tornik550]

I have dual weber 40 idf's. I cannot get the mixture correct no matter of the changes that I have made. I foul the plugs with dry black soot in only minutes. The car runs fairly well. Could be fine tuned however right now I am working on gross tuning. Heres the background info-

Setup-
-1.7l case now 2.27l by changing jugs to 96mm and crank to 78.5mm
-2.0l heads (I also have stock 1.7l heads, I have had the same issue with both heads)
-A "fairly aggressive webcam camshaft setup for carbs". I do not know the exact lift and such. The previous owner increased the displacement from 1.7l to 2.0l. He changed the cam when he rebuilt the engine. When I rebuilt the engine, I used the same cam. I had this rich mixture issue before and after my rebuild.

Carb info-
-Dual weber 40 idf's freshly rebuilt with new needles and seats
-main jets 120
-air correction jets 200
-tubes- f11
-idle jets 50
-vents 32mm
-floats set at 10mm (rich mixture), 11mm (rich mixture), 12mm (rich mixture)
-fuel pressure at 3.5

Other Info about my engine-
-MSD 6al ignition
-MSD Blaster 2 Coil
-Bosch 050 distributor with pertronix
-Autolite 63 spark plugs gapped at .030

I have tried a few things however I have not been able to change the problem. I only have a set of larger mains which obviously didn't help the issue. I have checked to make sure the needle is seating properly. I have removed the air correction jets to see what would happen- no major change in the mixture. I have a set of 34mm vents on the way however I doubt that will change much. It seems to me that with the carb setup that I currently have, I shouldn't be fouling the plugs after running the engine for only a minute.

Any ideas would be greatly appreciated.

(Yes, I did post something similar on 914Club. I am trying to look for as many ideas as I can find).

[tornik550]

I have kind of an embarrassing/funny story. Tonight, I decided to take the my carbs apart completely to see if I had missed anything when I rebuilt them. I found that ALL 4 of the starter valves were completely stuck. They would not move at all. They looked like they were closed however I think they were slightly open dumping fuel into the engine. I slowly worked them free, cleaned everything again, reassembled everything. Started the engine. Still had some black smoke but nowhere near as bad. I thought that the engine ran rough but not horribly bad. I checked the spark plugs and they were much better. I then realized that I forgot to reinstall the jet stacks!!! What an idiot!!! Anyways, I reinstalled the jet stacks and the engine runs so smooth. The spark plugs look perfect! Now I can fine tune everything.
I greatly appreciate everyones help. There is no way that I could have fixed the problem without everyones assistance. THANK YOU!!!!!!! (IMG:style_emoticons/default/smilie_pokal.gif)