The HD Heavy Breather on mine gets serviced whenever it goes gray and has been on there since new. It now has over 30K on it, and the other day I decided to remove the runner and clean the throttle body. I was surprised and pleased to see zero crud in there - everything was spotless all the way through. Don’t know if it’s attributable to my frequent clean and oil maintenance on the filter or simply the luck of the draw, but it made me one happy camper. It may have something to do with the intake runner design also; with the forward sweep providing kind of a ram air effect like the early hemis.

 

My filter turns gray 500 miles after oiling. How often are you cleaning and oiling your filter? Do you do it per instructions or just do it your way? What product are you using to clean and oil?

I remember reading some K&N or HD documentation that said the element will turn gray and that does not mean it needs oiled or that it is dirty (I wrote a note in my manual after reading it).

 

"These washable and rechargeable filters use a special coating to help filter fine particles from the incoming air. With time, the oil in the filter will dissipate and the element will begin to turn gray. Clean the surface and renew the original red color with an application of K&N Air Filter Care products.

I do ours about every oil change which is about 3500 miles on average..they are pretty filthy by that point but the layer of filth blocks more fine silty sandy airborne contaminants from entering the engine and doesn't get to the point where it robs performance

 

You do know that K&N filtration actually improves with some dirt in the filter, right? They truly rarely need service. You shouldn't have to clean it for at least 20K miles. Yes, they get a little ugly looking, but they are still working just as intended.

 

i think I acknowledged that by stating "but the layer of filth blocks more fine silty sandy airborne contaminants"......i can't get myself to let them go beyond getting filthy..old habits won't go away from my dirt bike and mx years dating back to the 1970s where we cleaned the AFs after about every race...don't see myself changing my maintenance regimen but others can obviously do as they wish

 

Interesting. Growing up and racing in sandy Florida we were always taught to not clean the filters on our bikes until after a meet because of the danger of introducing contaminants between heats.
Filtering always got better after a few runs. Always running a fresh filter allowed more fine particles in. Never washed one during an event and put it back on either.

Like you said I guess, people do different stuff.

 

lots of dust and mud in the PNW was the rule, a few sandy tracks here and there...they just got really caked and gross really quick a lot..later on used the Uni two stage filters and would oil them pretty heavily...we pretty much learned what to do from the Pros, which was also most everyone used Golden Spectro premix and Bel Ray GearSaver exclusively

edit: when I said race I meant after 2 motos, before the next 'race weekend'..and generally changed the gearbox fluid every other 'race'..but the pros probably did top ends every other race weekend..LOL those guys abused those bikes! The clay mud up here is nasty as hell..Washougal was our home track and they have held a National here every year since 1980

me back in High School..no FF helmet then surprised I still have original teeth!

 

There is no real big reason why the oil breather can (or filter) can't stay in the air filter compartment, just check it every month or so, and keep an eye on the air filter as well.

And to the guy who thinks that oil vapor going into a very hot engine is ok, I prefer that my engine breathes clean air, not air contaminated with OIL.

 

K&N says if you can't see the wires anymore then it needs cleaning.

 

and that's before 5000 miles for us for sure, however, we're using the SE High Flow kits and the face of the AF is what gets caked up more frequently than say the SE HB perhaps since its 'end cap' is what gets Mother Nature's full force and the AF itself isn't subject to as much full on debris..when I take the AF out the top is still red and the bottom is getting sooty looking