You can easily screw up the fit so, before you do anything test the fit, it might be ok. Put the clutch on with less than full torque and see if you can pull it off by hand with reasonable force. If not it’s a good fit. If you have to lap it don’t use anything course, you want 800 grit aluminum oxide or something similar. You want the taper to grip mostly on the big end so put a TINY bit of grit on the small end and work it in. Test often.
FAA certified jet engine and aircraft technician,
Nicholson Speedway class champion 2001,
Yamaha KT100 Service Center,
41 years karting experience