First word: GREASE! The clutch lifters on these bikes wear more because there is much more shifting going on. Grease those lifters!
We tried all kinds of clutch mods. The stock clutch would wear because of the slanted cork block faces, which were designed to let the oiled plates squish out the oil slowly and ease the engagement (part of the “smooth 4 effort” of the 500). Heavy-handed throttles then caused plate heating and warpage, making the faces engage less, then they wore quickly.
Barnett jumped in with their superior friction plates, but they were thicker, so their sets had 1 less plate pair than the Honda set. Result: same grip, less life. Even worse: the Barnett cork bits wear the oil pumps, causing low oil pressure after a while.
Solution: today, the plates are available with square-cut cork faces. Find these and use them. And, replace the steel ones, too. They’re warped if you have 10,000 miles on them, believe it. Also, DON’T run Valvoline or Havoline oil. These excellent oils overlube the plates and make them slip. Instead, use Castrol (best) or Torco (next best) oils. Castrol and Honda worked together in the 1970s to get the right blend: trust ‘em.
If you’re drag-racing: get the Honda slanted-cork plates and put them in backwards. Put the steel ones in backwards, too. They’ll grab like a spline clutch and break theat rear wheel free at the green light!