I think I did a bad thing.
You know how you have to have the clutch disengaged while feeding the drive chain onto the engine sprocket. So, I was pushing the clutch arm towards the engine to keep the clutch disengaged with my left hand while trying to feed the chain onto the sprocket with my right hand. A big POP comes from inside the engine, and now the clutch return spring doesn't work. I can manually engage or disengage the clutch by moving the arm back and forth, but there no longer is any spring tension keeping it engaged. Did I break a spring?