hmm this is super similar to how mine is, did you keep the track covered or ditch that? also how long do your pre filters last? Ive been thinking about trying to enclose the area with outerwears material but i have a funny feeling it will always fill with snow. Do you ever get snow through to the point of having issues? its mostly the dry days that really get me screwed up. We had a pretty wet pow day recently and it was much less of an issue of course.
I ditched track cover as more snow just built up on the cover. I say about max 3 months on the filters if you are riding alot, then they lose their water proofing.
Before I got it all figured out I had to excavate snow from inside my carb and I had a water intake seizure. Snow wiped all the oil off the piston on the intake side from top of port down. Lower half of cylinder on the intake side was all smeared with piston aluminum.