Is black carbon coming out of my muffler a bad thing? I just got the 280 kit from xrs only and a hotcam. Just finished my first 20 miles. Should I change the oil and filter now? I have noticed that whenever I rev my engine past 6000 rpms in nuetral black carbon spits out. I stuck my hand in front of it and when I looked at my hand it had carbon all over it. It feels like steam. I am currently running gn4 10w40 without moly. I am burning 93 octane gas. I was curious today and took my spark plug out to look at it concerned that maybe my jetting is to rich??? When I took it out it did have black carbon all over it!! Does that mean jetting is too rich??? It has the same jetting it had before the big bore. The jets came with the xrs only pipe I got from them. They said that the jetting should work just fine. ANY HELP IS APPRECIATED!!!!!