My old faithful Ryobi motor tool quit and of course, tore it apart to fix it. Carried it to the house to fix the switch that had failed.  After getting it going again I could not find the piece that held the shaft locking button up off the shaft.  So back to the shop to look for it. No luck but..... I did find a part of an apex seal, the triangular end piece.  Can these fall out?  It has been about 2 years since the engine ran. It ran rough but very rich so it didn't seem like bad compression. 

Does anyone know if the seals Atkins was selling a few years ago were one piece or 3? I don't remember its been so long since I put the engine together.  The invoice just says 2mm seal  ( I said a few years, the invoice is dated 5-26-2000).  I can't figure how this piece got where it was, 3 feet from the engine and I had put the cast iron manifold on a few months ago and only turned the engine over by hand while fitting belts.

Any guesses?

Wendell