Hello all I changed the oil in my 03 650S today and when I filled the oil I leaned the bike upright and the mark was at full. I put 2.5 qts in the bike. Once I fired it up and went inside for a bit I came back out and the oil level barley registers in the window at all. It hasn't leaked a drop. I am using a K&N air filter and have read that this filter doesn't allow the oil to drain after the engine shuts off. Just wanted to get some opinions from you all before I go out and overfill her. Thanks in advance for the help.