new CBZ

Hi I am Ranjit Tripathy from HYD. I purchased the new CBZ 25th MAR 2007.Around 20 days. And i am very much disappointed with this bike as well as the dealer. There is very big jerking sound comming on the bike and I show the bike to showroom engg around 3 times he is doing some think, at the time of deliver it is ok but after 1 or 2 days again it was start the sound. Now a days sound is too high. So Pls suggest me how can I resolve the problem