If it is running fine except the plugs fouling I'd try the D7EA plugs first without adjusting anything else. Only change one variable at a time. If all else is fine it could be that simple. Dialing in the air bleeds isn't going to affect anything at cruising rpm's and that seems to be where...
Here is a link to an explanation about the heat ranges. I agree with Stabler that Cycle X is known for their quality and doubt it's the carbs.
http://www.ngksparkplugs.com/tech_support/spark_plugs/p2.asp?mode=nml
The problem isn't your carbs but the heat range of your plugs. If your plugs are the wrong heat range they will not keep fouling burnt off and will foul out.