I continue to get black oily "stuff" from my spark arrestor. I have switched from a 150 to 148 and 48 to 42 slow jet. I have repacked my spark arrestor. Moved the needle jet up a notch to lean and put in a new air filter. I am running Castrol tts at 40:1. Running NGK b9eg spark plug. This combination produces a light brown spark plug with slight oil in both high and low RPM. The 1994 KDX 200 runs great, but the oil mess on the back fender and wheel drives me crazy. I have tried other oils with the same results. I have gone from 32:1 to 40:1 with no apparent difference in amount of "spungie" mess coming from my silencer. With Castrol tts full synthetic oil it only smokes very little under a heavy load or full excelleration. PLEASE HELP!!!!