After only 6000 miles from new I was told the belt and pulleys on my sportster were badly worn and needed replacing. Since this was done I have a whinning noise that appears between 40_50 mph. If I accelerate it disappears and also drop below 40. It has been rechecked by dealer and told it was somthing that happens with some belts. The only time it disappeared was when the dealer sprayed the belt with sillicon but came back after about a week. Is the belt too tight? The noise appears after riding for a short while so only starts once something wams up. Any tips on how to rid or something to put on belt.