About once every 1 to 1 1/2 months. Sorry to disappoint you but I pay to have this done. It is a bit expensive but I would much rather have someone who knew what they were doing work on my steed than me who only fumbles through with this type of thing. I will wire you a house, build you the finest cabinets, create you the greenest lawn, and show you how to manage a fleet of vehicles. But change the oil on a bike :yield: