2001 vstar 650 custom hypercharger and rejet kit and still feels like its bogging and like sputtering?

i am having a issue i bought a hypercharger and put it on my 2001 vstar 650 custom i think it has after market pipes but im not to surebut it felt fine at stock but i wanted to upgrade but now it felt like it was starving for fuel and it calls for the rejet kit so i purchased that put it in it came with 3 diffrent jets a 117.5 / 120 / 122.5 and idle screw i tryed the 120 and 122.5 and when i get into it boggs like sputtering and backfiring when i get into like half way on the throttle and its driving me crazy cause i cant figure why so someone please help thanks