Hey PJ,
Far be it for me to point out that you ALREADY HAVE the Clutch Pressure Plate and Six Compression Spring Clutch System that Barnett has so shamelessly COPIED except their Pressure Plate is powder coated Purple! (Which you CAN"T See once you put the clutch cover back on!! Never did understand that one!) And far be it for me to point out that your Clutch System is 37 years old! The issue I HAVE with the Carbon Fiber Barnett Friction Discs is they generate a tremendous amount of heat which has to be absorbed by the engine oil and radiator coolant. Plus, those carbon fiber clutch friction discs get a little "cranky" when they are cold. Unless you are "Racing" this motorcycle, you may want to have a look at Genuine Yamaha Clutch Friction Discs and a good set of EBC Heavy Duty Compression Springs! That should last you another 37 years or so, and leave a few extra bucks in your bank account! Just sayin".
Earl