Hey Wicked, From what I understand and BikeBerry is saying, that spring is no longer installed in the new engines. I've always said it's not really needed anyway, now the factory agrees with me. I don't know why your clutch was stuck, perhaps put together too tight at the factory, but that little spring could really have nothing to do with it. It's not strong enough to hold anything much more than the clutch plate slightly away from the pads. It's not strong enough to JAM anything.
Anyway, Glad yer up and running. Sounds like you put it together right,
Good Luck bro,