To change the oil on a Harley-Davidson motorcycle, vent the oil system, disconnect the drain tube, drain the old oil, remove and replace the oil filter and refill the oil tank. The process is simple and only requires a few common tools, a pan to drain the oil into and a funnel to refill the system. The location of some elements may vary depending on the model of motorcycle, but the procedure is similar for most Harleys.
Vent the system by removing the oil filler cap. It is located on the oil tank, typically under the seat on the right side of the bike. Locate the drain tube, which is usually directly behind the primary and in front of the rear tire. It is the only hose with screw-type hose clamps. All of the other hoses have crimp-style clamps.
Place a drain pan to collect the old oil under the drain tube and disconnect the hose clamp holding the tube to the frame. Slide the tube off and let it drain completely into the pan. Reconnect the hose when it stops dripping oil.
Locate the oil filter that is behind the down tubes and directly in front of the first cylinder and motor casing. It is usually black or chrome but may be white. Place a piece of cardboard under the filter to let the oil drain into the waste pan. Unscrew and remove the old filter. Put a couple of ounces of oil into the new filter and rub a thin bead around the rubber seal. Screw the new filter in place hand-tight.
Refill the crankcase with the correct type of oil and replace the cap.