My bike is a 996R and sometimes when I let go of the throttel or slow down quickly I have a backfiring type sound, BUT its not from the exhust, It sounds like at the front of the engine is sucking in air loudly. I cant explain it, it makes a funny noise but doesnt sound like motor noise more like compressing air ???? Doesnt always do this and ONLY when deaccerlerating never when accellerating.
maybe my desription is no help to all you gurus out there, but I cant explain it any other way

Anyone have a clue what it could be as I dont lol