I went to change the oilf filter for the 1st time on this bike today. I had ordered anOEM filter. When I pulled the filter I saw that the engine side of the filter had 2 holes about a 1/4" in diameter that went into a 'male' type of receiver on the case and the filter I got does not have those. I also have a 450WR and it is just flat as well. Any Idea, maybe the old filter gasket stayed in the case when pulled??