'09 AVL , sounds like an exhaust leak at the head, but no evidence of soot, a mechanic at work suggested unseated ring, which would score the piston. The oil was quite clean, but became black after only 300 miles. Can be very hard to start in morning, no more one kicks. Sounds like loose nuts on the front fender, removed them, no change, so it is mechanical. Mostly happens under load, 3rd gear and up. 8300 miles. Almost entirely spent its life doing short 8 mile commute to work, or coffee shop. Could it be due for decarbonization? Considering getting an aircraft leak down tester from aircraft spruce. No smoke from exhaust. I can feel puffs of air coming from my duckbill breather. Drained oil, no broken parts. Riding bicycle now. Ready for a teardown if necessary. Thanks, Matt