gstark The reason you only have the idle screws out 1/2 turn is because of how much transfer slot you have showing. You need about .020 - .030 of slot showing. If opening the secondary thing does not work out. You drill the existing hole in the primaries to 3/32" and see how it idles. step it up a little bit until you get the correct amount of transfer slot showing. You definately have a lack of airflow problem at idle. This is common with a good performance engine. Do not overlook the other causes of excessively rich idle, float level adjustment and powervalve leakage.