I am on my second XS650 and have the same clutch woes as on my first, dragging and almost impossible to get into neutral while standing still, it's all fairly well on start up but when warm it's a pain, i have replaced everything except the mushroom and basket, the basket is as good as new so we can discount that the mushroom has a little dimple where the ball bearing pushes it slightly off centre, it is also a little to small in diameter for the hole in the shaft both of which show no signs of wear, because of this when the clutch is operated the mushroom shaft goes offset in the shaft thereby when clutch separates it does not do it squarely leaving one side just touching causing the drag (theory), had the mushroom a much larger contact patch and better fitting shaft like on my KZ1000 mushroom it would open more squarely, the six plate is better as it has the conical spring instead of a seventh plate, this helps to push the plates away, now i am going to work on a modification and experiment using an engine valve with the same stem diameter, providing the mushroom part is compatible, and a shorter push rod, the longer stem on the valve will minimise offset, naturaly the valve head will have to be trimmed and the face polished, lets have some thoughts on this guys.