your idle co has nothing to do with boost fueling, there is a little box on side of metering head that when taken of(be careful when un doing it as fuel under pressure squirts out at first so have a rag handy) has a little flat headed screw in centre, remove this and under that is a tiny allen key head turn this clockwise to increase fuel under load. you have to turn it a little then re assemble to see results and repeat till desired level is attained, you should also use a wide band afr in stead to set fuel under load, co is really only used for idle levels and you could do with dropping that closer to 2 if poss. also when you adjust load fuelling you will have to re set idle after hope some of this helps, but if your not too sure get along to a good tuner cost you 100 and you can watch what they do for future