[kz1000st]

That wouldn't be the worst idea but the old ones might just be glazed too. Japanese scooters should last a long time and neither of my Chinese scooters with 10,000 and 8,500 are slipping. You would think a Yamaha would be immune to problems. I assume the belt is the right size so the answer is probably something simple like the variator or clutch bell need a light sanding. Try that first before new clutch arms.