I have a 2005 600 classic. How high should the R.P.M.'s get before the sled begins to move? When I take off from idle, the R.P.M.'s seem like they build a too little high(4500), then all at once the takes off like a shot. I know this is what most of the younger crowd wants, however I would like I little smoother power delivery. I bought the machine with 3000 miles on it. I thought it might need a new belt. Any thoughts?