I know there are some naysayers out there, but proof trumps rumor every time.
Replaced my valves in the Teryx. Now the factory loves to blame it on maintenance, more specifically, the air filter.
Factory Kawi foam air filters, pre-oiled and right out of the package. Once again, light coating of dust in the intake...everything is sealed up, including greasing the foam end-seal.
Going back to my K&N that leaves NO dust in the intake. No more foam filters for me.