ORIGINAL: had enough

Not long enough,
Try cleaning the bearing with some brake cleaner and reinstalling it
somethimes they get all gummed up with oil residue and the little roller bearing just are slipping, not grabbing

If you've never taken the back off the engien before be very carful not to let the spool come out of the pull start housing, if you do you'll be sorry while you're trying to rewind that damn spring