Well, I think I figured it out. I put a smaller main jet in there: size 55 (stock is 58). And now the bike is running phenonomenally. I'm at sea-level (Gulf Coast). I'll be paying close attention to make sure the 55 size doesn't cause any overheating problem. I thought all new stock bikes are always jet'ed lean to satisfy EPA. So it never occur to me that my bike could be rich from the factory. Or maybe it's the ethanol in the gas nowadays.