I don't know if my last post to this link entered correctly so I will post it here. There are 2 types of idle circuits on all of the carbs. we are using. This link may help determine where to go in troubleshooting. I have a delorto carb, but the link is for the system NOT the brand. Hope it helps!
http://www.flydiver.com/HTML/Delorto%20Carburetor%20Tuning%20Guide.html
