So far now, riding for a few months now I'm experiencing some weird flapping noises. Usually it only happens in the first 10 min of riding, if i rev or downshift and rev match I hear the valves or something flapping. When I lightly reved today it just made a huge pop but the bikes was running normal. Only has 5000 miles. Usually after about 10 minutes of riding it stops and everything's normal. Anyone have any idea what it might be.