I need some help, I have a 03 sportster 1200 custom. It ran fine but popped back through the carb every once in a while while riding. Someone suggested cleaning the jets. I took the carb off and cleaned out everything ( yes I have done this before on other carbs) while the carb was off I noticed some exhaust nuts missing and a broken stud. I replaced the nuts and repaired the broken stud and put in new exhaust gaskets. Now it runs like **** if it runs at all. It burns rich no matter what I do with the adjustment screw and pours black smoke. I took the carb back apart and inspected everything, all looks normal. I pulled the plugs that were both black and cleaned them. I checked for fire and they both have it. I put them back in and still the same problem. I went to pull them out again and noticed that the rear cylinder was almost to hot to touch and the front was still cold, this is only running it for bout a minute. I let it cool off and pulled the plugs, just what I thought I would see. The rear plug was black and the front was still clean ( and dry). I don't know what I did to make such a dramatic change. The smoke out is here this weekend so now I am pushing for time.

 

`Sounds like you may have forgotten to put in a part or gasket from your kit, or used the wrong kit. Other than that not enough info. to help you.