2001 Volvo Penta 3.0 GSM-A with Holley carb. I adjusted the idle mixture screws for best rpm/vacuum reading. The rpms increased as screws turned in (leaner) from the starting point of 1.5 turns out. Both screws now sit about 1.0 turns out. I can't slow the idle down with curb idle screw. The curb idle screw is all the way out and no longer contacting the throttle stop on the linkage.