
Originally Posted by
racerx
Scarred plates go hand-in-hand with corrosion and heavy clutch wear. Dunno about the "cheese grater effect" per se, slotted/drilled brake rotors don't eat brake pads. If you're talking about rust pits, then the friction linings would wear quickly until the rust was polished away. That would happen very quickly. More likely, the overall stack height of the clutch pack was below spec and those vintage original clutch springs have gotten tired after 37 years.
These engines pre-date current synthetic formula bike oils by a couple of decades. Clutch slippage has been reported when using synth and the fix usually involves new friction discs. Frankly, I'd pop for new springs, plates & discs and be done with it.