So as I noted in my last post, I recently changed all the oil in my bike. Ran perfectly (after the leak repair) for a few days. Since then there's been some sort of knocking/flapping/tapping noise coming from what seems like the transmission. It's a fairly regular knock, and only happens in neutral with the clutch out. Pull the clutch in and it stops, put the bike in 1st and let the wheel spin, and it stops, back in neutral with the clutch in, stops, let the clutch out, and there it is again. Fairly confused as to why this came about since all that's happened is an oil drain and fill. Used Liqui-Moly Synthetic Racing Gear Oil, 75W-90 from Beemer Boneyard with a tad of Lubro-Moly MoS2. Any ideas?