AVS 650 hesitation

Sounds like the accelerator pump is not kicking on right away. Look down the carb and press back on the pedal linkage the accelerator pump squirt should start immediately, if not then there is an issue with the accelerator pump system.
I inspected it, it is the stock one should I upgrade it with the better one edelbrock makes? I tried moving the slots on slot made it worse the other just about the same