I gave started my `1989 kx 125 and gave it a good run about 5 mins today and by the end there was a few drips of black oil coming out my silencer...it was quite thick....this isnt normal...? :(
jus some unused, unburned 2-stroke oil. the fact that it black tells me the bike dosen't get hot enough to burn it off more in the silencer. also, you might be running a ratio with too much oil, rather than gas. don't sweat it.