In preparation for a race last weekend, I prepped two air filters with NoToil oil. One (Twin Air) went in the YZ250F, the other (stock) in a zip-lock bag all oiled and ready to go, just in case.
Last night I wanted to change the filter in my WR400, and went to the one in the plastic bag. Youza!! The glue holding the outer course filter on the inner core was pretty much gone, and the foam pieces were of course falling apart.
I've done this before, and didnt' have this problem. However, I did have the glue loosen up once. I got the smart idea to use hot water for the Notoil cleaner - bad move! The glue melted. After the filter cooled however, the glue went back together and it worked fine (no, it wasn't this particular filter)
Anyone else experience this? All I can say is be careful!