Appears the piece just fell out. If you look in behind the spark plug, there is cooling fins. Shook out between these fins after???No Bang Bong Squeeekk??? Bike .running after the hole there or immediate stop
Valve Problems Right exhaust ???
Rather big hit to shoot that piece out
I'm betting you had a tappet nut wasn't tight, the tappet backed out, went over the top of the cam then wedged under it. They "usually just" break the oil fence behind the cam, guess you are the lucky one.....
View attachment 198144
Sorry.@gggGary You were right on. View attachment 198166