Dual 450'S (I know)..I can't get them to idle down. If I set the curb idle while running on the water I can get it to idle fine. But when I get on the throttle for a short time and them let off it wants to idle high. When I set the idle too low so it almost wants to die and then get on the throttle and let then it idles down right away to the too low setting. The throttle plates were drilled out years ago but I've always had this problem. I messed with the secondary throttle plates and it didn't like that. I left the curb idle where it's at and just upped the secondary plates about 1/8 turn. It didn't like that..Has a mag that works great and does not stick..big lope cam..I assume I'm in well into the transition slots..floats and fuel pressure are perfect..can I set the rear carb so it's closed more or what....thanks.