Checked the chain, especially my links. No obvious kinking. I thought maybe too much slack in the chain. Maybe the chain was rubbing on the top on the swing arm when coasting. Tightened the chain up a little, but still get the sound. Of course the chain could still be rubbing.

I looked at the front sprocket, which had a little play (looseness) in it in the direction you would install/remove the sprocket. I don't think the sprocket sticks out far enough for the washer to touch it. The washer is tightening up on the shaft before it touches the sprocket to remove any play. Is the washer supposed to be cupped any? Mine is practically flat. The play is maybe .25mm or so, 2 or 3 sheets of paper, not exactly sure, just enough where it will move.

I may just have to label the sound new sprockets and chain.