Okay so I recently bought my first bike, which is a 2007 Kawasaki Ninja 500R. I believe that is known as the ex500r on this forum. Anyways, I took it out for a test drive and being the dumb person I am, left the choke on all the way so that the bike was idling at 3 to 5000 RPM as I was driving in first gear. I realized my mistake and turned the choke off so that it was idling around 1200 RPM. After stalling the bike a few times the oil pressure light came on so I decided to take it home. When I checked the oil level gauge, I could not see any at all and so I decided to do a full oil change just to be safe. After brand new fresh oil and a fresh oil filter, the bike still idles below about a thousand RPM and when it gets around 900 RPM it begins to knock. I have no idea how to solve this issue and I need some help.