Look over the axle and other bearings.
At least you didn't toss #9 away thinking it was some useless piece...
Honestly, Paul . . . I almost did. I thought it went in the weedeater head to guide the shaft. Luckily, I kept it. Even more luckily, I pulled the starter cord out of the weedeater and had to disassemble it, which set me to thinking about that part. Somewhere . . . in the back of my mind . . . I had an image of that thing sliding into the back of the sprocket hub.
I re-installed the part last night and took it out for a "WFO" test, with no problems.
The seal is slightly wallered out, which tells me that the inner race is probably wallered as well. The bearing spun like a top, so maybe it'll last. I bet I shaved 20K miles of usable service life off of it, though.
I'll replace the seal when I change out the tire in a couple thousand miles.
Thanks folks!