Motorcycle Repair: carb, sporster, whent

Question
I have a 1990 sporster 1200 evolution I bought two years ago for most of the first year ran fine then developed a miss and poping until it warmed up and then it would just kick in I changed battery,coil plugs&wires checked all fuses cleaned all conection. but none of theese worked so I put it in shop told them what I had done and they called me a day later and told me that my intake was wharped,so I said ok fix that I took home rode fine whent to go on ride two days later started acting up again not as bad took back told me need to go bigger jets in carb I clean mine regarly so my question is is this so & which ones ? when I first start my bike I choke it and slowly push in till runs on own now when I go and ecellarate it misses you can see the tac jumpin fourth gear once the bike gets warm it kicks in runs great once I stop for more than five to ten minutes it does it again. I would thankful for your opion.

Answer
If your bike is running fine and then starts running bad, without making any changes, then your jets dont need changed. Over time jets do not change size! Also, I have never heard of an intake warping
Pull your plugs after riding and let me know what color they are
Good luck and happy riding
Mike