:BLAM:My 1988 vulcan which I bought used 3 months ago runs kind of rough between 4,000 & 5,000 rpm. Outside of that range it's ok. I checked the air filters. The previous owner changed them before selling them to me and made the soaking them in oil mistake, so I spent some time wringing out excess oil. One of the rabbit ears was cracked and I sealed the crack. I backed the pilot screws out to 2.125. I threw a bottle of gumout into the tank & drove it 100 miles. Still the same poor behavior between 4,000 & 5,000 rpm.Any suggestions?