Yesterday I took my 900 in for it's first oil change. The tech told me that if I ride it on the highway much, I should take the air filter cover off every 500 miles while holding a rag underneath and drain the oil. He said it's very common that the 900 blows oil up into the air filter and if you let it get too full it will get sucked into the filter and make it run rough. He also said most all he sees come in do it to some extent, but some more than others. Has anyone else found this with their 900?