We all try and get the most out of our bikes, and cleaning up the fuel passages seems to be the most popular. In another time of my life I raced Sail boats and the Hulls were worked on every spare moment trying to eek out a advantage. I remember seeing hulls that looked better then the finish on most cars. One weekend this guy pulls up with his boat which does not have a mirror finish and he kicked our butts. Talking to him he said that a not perfectly polished finish gave better performance by allowing a boundry layer of water to attach itself to the hull which in turn allowed the boat to move with less force, the boundry layer rolled rather then being drug. He never went finer then 400 when wetsanding his hull. Why would this not also be the case in the fuel passaages ? Maybe someone else has a thought on this.