I have a 2004 HD Sportster 883 custom. I recently put a set of Vance & Hines pipes on it. After I did this, my bike started to miss after it warmed up from 800-1800 rpms only. I was told by two different harley dealerships that the slo jet was the problem. The slo jet was a 42. I replaced it with a 45. Also, the main jet was 175. I replaced it with a 185. I drilled out the plug to get to the mixture screw. Everything adjusted correctly but the problem is still there. I would like to know if I am possibly going in the wrong direction and need to check the electrical system instead. Does anyone have any ideas?

It seems to me like you did something when you installed the exhaust system. All of the advice on the carb re-jet is good, however did you install new gaskets, did you damage the old ones?Is everything tight no exhaust leaks?If the problem did not exist before you worked on it then, go back to the last thing you did i.e (installed new exhaust) and work forward from there.

 

Since you can't fix it for jetting, then I would look for exhaust leaks. Make sure the gaskets are sealing properly and things are torqued to spec.

 

Save your typing fingers guys.The member that posted the question hasn't been here since 7-4-07.