2004 vinsion 500 issues

I know its not a honda guys but hoping somebody can help me,
I put a snorkel on it, 1 1/2 in all the way 1 90 and 2 45’s. rejetted the carb to 140 main and 40 pilot. fuel air mix screw was set to 1 7/8 like manual calls for.
Issue is can not give it full throttle, acts like it wants to die and back fires. any help would be appreciated.