thats definately not boost cut..as when u hit boost cut it kills ur ignition and ur stuck rolling down the road in a car going brrrr that does nothing when u put the foot down...until u kick the clutch in and realise its dead lol....well thats my experience in the 165 anyway....
there was a dude on here having 185 boost issues a few weeks ago..it sounded similar to urs but worse, check the little rubber connecter between ur IC and tb...i think he had split his or something