What is the plug supposed to look like on a properly jetted 450? Since the weather warming up, my plug color is off white color, with no residue. Its very clean with 2 hours on the plug. Am I too lean? Jetting is stock, only mod is a ride eng. fuel screw. What jetting should I be running at 500ft, 70-80 degree weather? Only have a RS-2 slip on for mods. Thanks!!