Need help engine missing part?

[Stevestark]

I was working on my bike and when I was working on the clutch it didn't fit right, I think something fell out if anyone know what it could be? I did find one piece laying around not sure if it's it
Any help is appreciated thanks!

 

[2door]

That pin you're holding, called a bucking bar, goes in the hole in the center of the sprocket. There should also be a ball bearing that goes in before the pin. It might still be in there, stuck in grease.

If the ball bearing is missing too you can replace it with one 5/16" or 8mm in diameter.

Lubricate all of those parts with a grease before reassembling.

Tom