Not sure what he has as hard evidence, but I am pretty sure Hondaman claims that the 10w40 recommendation in the manual is an error, and from my experience, I would agree. 10w40 is for collllllldddddd temperatures. How many here even consider getting the bike out when temperatures are below 40? (oh yeahh, mainly talking about 750's here, for smaller bikes guys I think 10w40 works fine)
I don't really know why I am even posting in this thread, as all this stuff has been posted a zillion times. If these engines have oil, they keep running. If they don't, they die really fast. And there are a million shades of grey in between these two extremes based on exactly what you dump in your tank/crankcase.