Honda-SOHC

Hi,
I found out the issue on my bike. It was the 23108-333-020 Secondary drive gear that was worn-out. Actually I do not see any pitting or any sign of worn on the gear but it is. Maybe you can measure it.
I changed gear to a new one on got rid of the sound like in the original post.

Kind Regards
Anders

My 1975 sounds exactly as Brian’s. Noice is only when you put load on drivetrain/engage clutch. I guess if it should be cam chain the noice should be all the time, without load also.