Last year I installed a K&N air filter on my YFZ450 (to replace the stock air filter). I have read articles that say the K&N filters allow a lot of dust/dirt into the engine; is that true? Am I better sticking with a foam filter? I was thinking of getting the OUTERWEARS Pre Filter at RockyMountain to slip over my K&N for extra protection. Thoughts?

 

I would recommend the outerwears and while i agree a foam filter like UNI probally protects better, I have never had a issue with a K&N.

I just switched from a Pro-Design UNI to a Trinity intake with K&N on mine.

 

I've ran K&N's in all 4 of my bikes, and been using them since 98'...I've never had a problem, but K&N's do work better when they're dirty....so if you run one, just lay off the cleaning everytime you go riding...or like stated before, use the precharger they sell...

 

K&N's work great. I have a K&N,outerwear and a cut lid on my raptor and it works great. I put on the outerwear and didnt feel a perfomance decrease at all. Order the outerwear from rocky mountain for protection and peace of mind. After a couple good rides look at the outerwear and think, i just stopped all that crap from getting in my engine. The foam filters may filter out more particles but they also block all the air to your engine. K&N with an outerwear equals the filtration quality of a foam filter with the air flow of an original K&N. Happy and clean riding.

 

In sand the k&n work great with outerwear ...but in really dusty conditions i would use a foam set up. It all depends on where you ride!

 

i have been running k&n air filters in my quads for years and have never had any problems or ever herd of anyone i know having any problems with them.

 

I run K&N of everything that I own. All my vehicles and my quad. I've never once had an issue with them. Just make sure that after you ride that you check and see if it needs cleaned. If it's dusty you probably need to clean it every or every other ride.