yamaha racer 686
Hard-core CEG'er
ok so my car spits black sut(sp) out the back. i read that it means its running rich. now i dont have any codes. the car is a se v6 with about 103,000 miles on it. as far sa i know all it has had is basic maintince. is there anyway to fix this?? i dont want the sut to ruin my new exhuast and tips