My '07 450 started running like garbage. I got it during Christmas and it has ran fine up until last week. Now it bogs and even stalls when I open the throttle quickly (for example coming out of a tight turn). It really only seems to happen when I go from fully closed to about half-way. It's also popping a little and it looks like blue flame coming out the exhaust (very faint). I've cleaned the carb and have the fuel mixture screw about 1 turn out. I tried 2 turns out but that didn't help. You guys are the smart ones so help me out. Should I change the pilot, the main, or could it be the valves? Thanks in advance for the advice. Oh yeah, I'm in SoCal at sea level.