Hes referring to the metal plates. You have three of them. The outer most plate(closest to the nut) is thinner. Get an extra thick one and replace the thin one. Then get a thinner washer. What the bell sits on. Most important is keeping the clutch cool and wet. Those clutches splash out and get hot. Ive been experimenting with fluids. When rebuilding the clutch make sure you deglaze the surfaces on all the pads and plates. Also make sure the bike is on its side when assembling the clutch. Put the the pieces back in one at a time and make sure you tap them all the way down. As far as tuning that clutch, its all on the springs. I just tried doubling the springs to make the clutch grab later. Did very little. want to find springs about ten times the stiffness. That should get me closer to the power band.