I took off the valve cover and discovered this piece broken off from the valve assembly towards the front of the motorcycle on the right side:
Here is where the piece broke off from the assembly:
Here is a shot of the entire front valve assembly:
A shot from the left of the motor. The valve assembly with the broken piece is to the left (front of the motorcycle).
Glad to finally have found something that is definitely broken so I am clear as to what the problem is, but wondering what else I need to look into. The starter was turning the engine decent before, but now it seems the starter is seized up and the cam chain and gears in that last picture are not turning at all. What part is that that broke? What more do I need to investigate besides replacing that one part?