The manual I have for a K6-600 oil change says 2.6 quarts of oil are required with a filter change but I don't see anything in the sight glass after the recommended 3 minute settling time (or even an hour). Does my K6-750 need the same volume of oil? If it does what's going on? The only thing I can think of is I installed a K&N filter that says it has a check valve to keep oil in the filter to prevent dry starts, does the stock filter have one? Is this the reason my oil looks low? I defiantly don't want to overfill so should I run the bike with nothing showing in the sight glass?