I have a 1998 YZ 400 that I am having some issues with. It has a problem idling and a hiccup right off the bottom when you first start to open the throttle. I have been told it could be jetting, valves, accelerator pump, etc. I wanted to get some feedback. Please let me know what you guys think. It is driving me nuts. Also the idle adjust is all the way up and it will barely idle and usually just die. I ride it on the street and have to keep revving it at the light so it will stay running. It runs fine but idles high with the choke on. It has a new motor, and the only thing I know is that the main jet is a 175 and it has a DSP pipe on it. Thanks in advance.