I have a tube of this stuff that you're supposed to put on the rubber edge of the air filter to help seal it against the metal of the backing plate and inside of the cover, but I ran out and my local stores don't seem to have it. Does anyone have any suggestions for a substitute?

 

This may help

https://www.google.com/#q=k%26n+sealing+grease


https://www.google.com/#q=k%26n%20se...%20alternative

 

Maybe you can use the same stuff you put on the sealing edge of your car or truck's air filter element. Oh, wait ...

 

i used to use a good wheel bearing grease on my Husky's..... thin film around the base where the filter mounted...don't need much. But then, that filter was off between weekend races and cleaned and prepped.... but still, a good waterproof grease will accomplish what you're after. sometimes it's a cheaper alternative than some of that specialized product....just saying.....

 

Every k&n I've had never came with sealing grease. I always just put the airfilter in and thats it.

 

Any hi-temp grease will work

 

I always greased the airfilter to airbox connection on all my dirtbikes. I have never done it on any streetbike. If you are dead set on continuing the practice almost any grease will do that you have on hand.