Hey everyone, I have a 2004 450r. Everything is stock except i removed my air box lid and has k&n filter, I ride from 6000-8000 elevation. Main is 118 pilot is 48s, before I removed the lid the bike ran great. Now it dies if you stab the throttle at any givin point while riding or sitting still. And will die if you try to wheelie. Also when on top end runs like a champ untill you hit a jump unpon landing the engine will immediately bog down when applying throttle untill it dies, or if you pump the throttle 4 or 5 times itll be back to good top end acceleration and pull but no low end torque.