Loud ticking noise. (99’ Yamaha SR/ST 250) Any ideas?

Video and sound of the “Ticking noise”.
https://imgur.com/a/3IOpz7D

It seems very loud when I press my ear into the tank, So the video showcases that aspect very well.
It’s very worrying that I don’t know where it’s comming from. Piston, Piston ring and Valves all seems very fine. So I ask the internet humbly for any advise or ideas you can give me.
This is supposed to be the bike that I get some enjoyment from before getting a new one. But I don’t dare to ride very far with an engine sounding like that.