Isn't the 20-50 vis oil a little heavy? If you hear this after start up its probably due to the fact that the cam chain tensioners aren't "pumping up" with oil fast enough. A lighter weight oil might solve this problem. I had this issue with my 950 and it got worse until I was hearing the rattle sound when at idle and the engine was warm. I did a lot of research and all signs pointed to a worn oil pump piston which was only barely able to maintain oil pressure at idle. I replaced it and the problem went away immediately! And this was at 33K mi.
Wind in my hair, bugs in my teeth!