Bill The 03 Fatboy TC88 carbed engine came with a #45 pilot jet, you will need to replace it with a #48 pilot jet, I strongly suggest the SE air cleaner kit. but it can be done either way, the carb done over with the SE air cleaner kit will give you about 2-3 hp over a stock air cleaner. it's your call. get just the pilot jet or the both, let me know when you get the parts. Chet PS I have heard rumors of nice weather this comming weekend!