On idle, it runs perfectly fine. As soon as the throttle is touched, it starts to bog and dies. We have installed a new fuel pump, new injector, and a new fuel pressure regulator. The fuel pump and injector are receiving proper voltage, and the battery voltage does not drop when we try to rev it. The ATV is a 2006 Suzuki LTR 450 Quadracer. What could be causing this issue?