What year bike do you have ?
Starting with the '81 model year bikes, the clutch arm parts were changed from the 'first generation' R65's .
My first guess would be a tear in the rubber boot/cup part #7 .
With the '81 and later bikes, the spring, #14 is inside of the boot, if you don't loosen the worm gear clamp on the boot before removing the clutch arm pivot bolt, the spring will expand and put excess pressure on the boot and possibly tear it .
I've only let that happen once .