Quote Originally Posted by RATTROD400 View Post
It a 750 holley just tore it apart everything was clean put it back together will run but rough played the idle fuel mixture screws no change stated pulling plugs they look burnt seemed like it started this after they switched to winter gas
Are you sure the idle screw didn't back out?? It happens! Also, if the fuel/air mixture screws don't make any change, there is a problem with the carb!