Now I know the correct way to check mixture settings, (take the bike to Steptoe!), but can anyone tell me why, after a 160 run down the M4 at something close to the legal limit, the inside of my standard GS can was a very light tan colour, yet, since fitting a Remus Evolution can with baffle tube in, the bike feels more responsive, yet the inside of the exhaust is always sooty black no matter where or how I ride?? I'm not worried, just curious 