I posted here because I usually get great answers. I am working on a totally thrashed 96 KTM50SXR. It does not have an air filter, and I am having a hard time finding parts on line. The filter box is a full open top, bottom carb feed that is square except for the back. The back is cupped shaped to clear the shock. I was thinking of using filter foam and just building my own to stuff down after cutting to fit. So is there a bulk filter foam that comes in squares, who makes it, and where do I get it? Any help would be appreciated.