[Hotfingrs]

THE NOS could be a source of your problem. Most systems run a fuel line to provide extra gas when the NOS is activated. Not knowing what setup you have, I'd check into that first. If you don't plan on using the NOS I'd take it off and get rid of that variable, then we can work on adjusting the carb. I still would need to know what jet sizes are in the carb...also you really need to use a vacuum gage when you adjust the idle screws...