I have a 00 610sm e start. I put two straight through tailpipes on it and trying to get the jetting right to suit. There is a surge/stutter when trying to hold a steady speed on low throttle and getting some loud popping on decel. I have changed the main jet to 185 which has helped a little with the popping. The carb is a dellorto and is currently running Jet sizes: Main= 180 changed to 185 Idle = 50 Start= 50 Atomiser= ab 260 Venturi valve= 300 Needle= k32 Fuel screw=2 turns out Any advice will be much appreciated, thanks.