I see here in norway that many of the old high mileage srx's that are for sale have new primaries and secondaries. whats up with that? I had a 98 600 which I rode for over 6000 miles, I never dreamt of replacing the clutches
the 8DN belt runs very hot and overtime can cause the sheaves to crack, requiring replacement (and a lot of the times it is cheaper to get a new primary if other parts are starting to wear as well)
the only thing i could think of for the secondary is that the primary blew up and messed up the secondary (i know this one from some sad experience). My yammy primary blew on my 97 sx at 9,000 rpm and went through the clutch guard, hood, powermadd box, bellypan, speedo cable, secondary, footwell, gauge pod, etc. Not a pretty site.
norwegon i can say from experance around 10000 klm if you have done springs allready you will need bushings for your primary cap secondary helix and iner sheave. buttons will need to be replaced on the secondary as well the bushings and pins on the wieghts and rollers.the towers wear to the point were new bushings on secondary are usless and you can tell by rocking most of these parts back and forth with no spring preasure on.these parts will go a long way but for good peformance and piece of mind i recommend doing these repairs if you see lots of belt dust around.