Revised version (reupload)

Valve seat cutting work with a valve seat cutter, and valve rubbing work with a valve wrapper.

● First time
0:00 Cylinder head inspection started
0:25 Rubbing valves
1:13 valve seat observation
2:21 valve seat cut
3:44 Valve rubbing with valve wrapper
4:30 Confirmation of using KOMYOTAN
5:37 Detailed observation of the valve seat using a microscope

● Additional work
6:53 valve seat cut
8:17 Confirmation by Komyotan
9:02 Valve rubbing with valve wrapper
10:40 Detailed observation of the valve seat using a microscope
11:25 Valve temporary assembly
13:39 Leak check using LED light source
14:11 Leakage check using kerosene