first off welcome to the hq
now for the banshee. sounds like your jetting is off. if its bogging when you first hit the throttle then you probably need to get a bigger pilot jet.
are you running stock carbs?
do a search on how to rejet stock carbs.
find out what your elevation is and what size jets your currently running and let me know. i can probably help you out.
two more thing, if its been sitting for a while i would recomend changing all fluids, before running it and becareful running the machine too long w the choke out, its not very good for the motor.
good luck and let me know if you need help getting at the jets?
peter