Ok you probably don't know my setup so I will tell you that first. It's a ZR600 EFI With AAEN twinn pipes, D&D Trial Chip, and Boysen Raceing reeds with a manually ajustable fuel pressure regulator. I just got back from my weekend sled trip and found that although the engine ran very well I have a bad bogging between 5000 and 7000 rpm. So bad that I have to feather the throtle to get it past that rpm range. I can't seen to tune it out. What could it be?