Any opinions for an '03 z400? I'm running K&N now but traditionally with other vehicles I've used Uni. Is one better than the other or are they just different types that perform basically the same function?

 

I've used them both and the UNI is it. I'd use the k&n on the street only but not behind someone eating dust. I have always found a small amout of dust inside the intake with a K&N. There will be guys who swear by the K&N but not I.

 

I concur. K&N breath better and allow more air in because they do not filter out fine dust which is not an issue on paved track or street but not effective off road allowing way too much dirt in the intake. However if you are not concerned about sucking in dirt, don't run any filter, that is what they do at the drag strip and you will get even better performance but you engine and carburetor wont last long.

 

I am definitely concerned about sucking in dirt! I usually recommend Uni to people but have no real backup for it. Sounds like I need to go back to the Uni.

 

So, here's another question. I did order a Uni last week for the z400. I'm used to seeing them with a rubber boot where it would connect to the intake. This one (the model for the z) has no rubber boot and is just a foam filter. Does that just go over the intake? Does it stay on okay like that? Should I order one that has the rubber boot instead?

 

Most of us get the po Design intake with a Uni filter. It allows you to use a clamp type filter. the intake boltes to the air box and you get a tight seal. Here's a link to one.
It's one of the best mods that you can make to your Z!!!

http://www.motoworldracing.com...r-Filter-kits-ATV.html