This was a very common occurrence with the 2010-2012 Polaris Sportsman 850, and I witnessed it firsthand when my father in law bought a new '11 Sportsman 850 SE that had this happen frequently. We'd be following him, and he'd hit a mudhole with an off camber rut, come out the other side and its blowing white smoke like a WWII destroyer laying down a smoke screen !!
It was so bad we couldn't ride through it for fear he had stopped ahead and we'd rear-end him. Two trips to the dealer with no resolution, so once it went out of warranty he traded it in on a Honda Pioneer. It had damn near a half a quart in the airbox, and I had warned him about it before he bought it, but he assumed they had fixed it for the '11 model year after the owners of the '10 models had raised such a stink about it.
We are all very curious about the new 500s, as info on them is extremely sparse, and I don't even think I've found any good YT videos that showcase them, so feel free to let us know your opinion on the 500.