The more you change your oil the better it is for the longevity of your motor. However, after you changed the oil and drain every last drop from the oil bag, not all of the dirty oil is removed from the bike. There could be up to 30 ounces of old oil sitting in the sump (lower end) of your motor. So after you changed out the oil and filter, then fill the oil bag up with clean oil and start the motor all the old dirty oil from the lower end mixes and contaminates the fresh oil before you ever hit the road. You could remove the drain plug from the case, but every time you do that you run the risk of stripping the threads when you've got an aluminum case with a steel plug. So what do you do to get all the dirty oil out and start with all new oil every time?
Rogue Chopper has come up with a way to change and flush all the old oil from the motor every time you change your oil. It is called the Scavenger total oil change system; and it's an effective way of changing out all of the oil in your engine. There are six different kits that will work for H-D style V-twin motorcycle engines. This is a good tool to have in your tool box at home if you are the kind of guy that likes to do your own services and a better setup to have if you are a shop owner to offer a complete oil change and mean it. The kits start at $59.95 for the Evo and $149.95 for Touring models. We wanted to show how easy and how well it works, so we got our hands on the Dyna kit.