Have two 500s. One very low mileage, the other I have a couple of sets of forks for. All clunk a bit when you hoist on centre stand.
Had the forks apart on the high mileage bike recently and also compared with the spare set. Of the four fork legs I found that the damping was uneven on two of them. Used the best two and seems better. The dampers are sealed and not made to service. Anyone had one apart, presumably there is nylon ring or the like inside that could be replaced or maybe the internal bore is worn/distorted?