I just put an HMF slip-on on my 450r and was also going to put a jet kit in, and remove the airbox lid and replace the stock filter. But I can't decide whether to go with a K&N or a UNI. I've heard of some people saying, " a K&N made my quad blow up." I don't know if I believe it, but at the same time do not want to take a risk. Also, how much better can another foam filter like the UNI be? Any help would be greatly appreciated. Thanks guys.

 

K&N all the way. If you ride around water (which is a bad idea anyway) put an outerwear on the filter for that occasional splash of water.