Kids are grown up and moved out, time to get a bike again and it's been 25 years. I've owned most of the 80's superbikes but now I'm looking at a 2007 CVO Road King Screaming Eagle. 19,000 kms. It had the "product upgrade" done in 2010. not knowing the 110 motor well, i noticed that at the end of the one pipe I have discoloring. Is this maybe just a bad tuning or could it be valves?