Got the telescoping magnet wand and fished inside through the only openings in the engine....nothing.As I said,I'm 99% sure I saw the "sparks" clear the frame when they launched,one towards the rear,pretty much no way that entered the engine,the other towards the front,both pieces most likely landed in the grass surrounding the area I was working in.Probed the space in the center of the engine below the cam chain and the spark plug holes with the magnet,I think I'm ok.If I had reason to believe something went in or knew for sure like dropping a nut or something in there I'd surely open the engine.