No matter what I do, there is always black splooge coming out of my exhaust during a ride. I have changed to a leaner needle (still 2nd clip from top), gone from (Stock-) 180 main to a 172 main, 50 pilot to a 45 pilot, 2.5 turns out on air screw out. Altitude 1700m, mix 40:1. Bike runs superb, just messy swingarm etc afterwards......Please help (Someone that has managed to sort this out)