whats the plug look like??
duz it backfire?
try the bigger jet 165? then work down
my gfs banshee near stocker (k&n filter) did the same when we brought it.. and i had to go from a 200 main jet to a 250 now it runs fine.. but the plug chop shows its a little lean.. putting pipes on it so ill rejet then
mine did the same thing had me stuffed.. then it was the stator ... RS...