I was told by the guy who sold me my 2003 yz450 that I shouldn't waste my money on an after market exhuast because none of them work as good as stock. Also I'm scared if I did change pipe I'd have to re-jet and I've had alot of problems with my klx 110 in doing that. My bike starts very easily right now. I never have even used hot start. It just always starts and I'm afaid to lose that quality. Any thoughts on these issuses??? Anyone???