I have a 2006 wide glide, 95cu, 211 cams, big radius pipes, power commander, K&N filter. After several months of the engine upgrade it developed a 4000 rpm hesitation at full throttle. I changed the plugs and plug wires, no change. I then had the injectors changes according to a HD service bulletin, the hesitation is now at 3500 and 5000 rmps. Any suggestion on what might be the cause?