We just aquired an 03 Sportster with 90 miles on it. Upon disassembling the carb, the pilot and main jets were restricted. We could not unclog the 42 pilot jet. We had a 45 here, so we installed it. The bike runs fine under medium to heavy acceleration. It seems to struggle a bit when taking off from a dead stop. It also seems to cut out at steady speed and low rpm, say at 45 mph in 4th gear. The bike has stock exhaust but has an air box from a 07 Sportster, which appears to have more air inlets then the original air cleaner. Read the self help but couldn"t find this particular problem. Any advise would be appreciated.