I have a 08 450 it starts but when i give it a little it just dies. It will start right back up and then when you give it some it dies out again. I have taken the carb apart and nothing looked out of place so i cleaned everything and put it all back together and then started it up and when i eased into the throttle it died. any idea what is going on? It has a big bore kit, cam, valves, and stock exhaust.