I have just purchased a 2008 Burgman 400 with only 427 miles on it. The wife never rode it and the guy got tired of it being in the garage. I hear a loud, deep frequency squeal or howl as I accelerate from a stop. It's of a very short duration and I think it stops when I feel the "drive system" fully engaged after a couple of seconds or so. It doesn't make the noise on the center stand when I slightly rev the engine nor with the rear brake on. Can someone guess what this may be ? .....serious, or not ? Thanks.