I was riding in the trails the other day and noticed my blaster would make a ping\knock sound at WOT. I am running 93 octane with pre-mix I have a FMF fatty pipe, Vforce 3 reeds, WIseco piston, vitos high comp head gasket. open air box lid. I am running a stock carb with stock settings except 270 main jet and spark plug is a br8es. I tried a plug chop and when I took the plug out it was covered in heavy black carbon. Is this a sign of being lean or rich and has anyone else ever experienced this problem? I also wanted to note that when ridding in the dunes my bike seems to overheat. After riding in loose sand for about 30-45 mins the bike died and wouldnt start until a 20 min. cooldown then it ran perfectly fine ......