I have done so many valve jobs on the older engines. It was usually the cause of hard restart when warm. We sold rebuilt mowers as well as fixing them. Sold about 40 or so a year and they all got the valves done on them.
I am annoyed at myself now though. I am missing my condenser pliers. Been years since I even changed a condenser so not sure the last time I saw them, one of the used every day in the shop tools (a long time ago).