Blow by?

Yesterday I changed to oil in my ranger, gave the underbody a good cleaning, and figured while I was in there I would check the air filter. The filter had a small amount of oil on it next to the crank case vent hose. From what I can find it sounds like "blow by" but I also read that polaris had a motor a couple of years ago that would push oil out of the vent during normal operation (an 850?). Is any one else seeing this? Any thoughts on what is causing this? My machine is a '14 900xp with 50 hours on it, air filter seemed to be seated well, oil may have been just above full before it was changed, and has been running fine other than throwing a code for the speed sensor.