having problems with the idle,mayb a vacume leak?

[bansheeboi22]

hey i just got the banshee all put back together after the topend rebuild, its jetted a little fat for the break in, but i had a problem when i was riding yesterday it would start to idle a little off and then just go crazy wide open throttle without me even being on the gas id hit the kill switch and that wouldnt kill it id have to choke it to kill it, other then this happening a couple times the thing rips, if anybody has any ideas what it could be, please help me out and post um up