K & N Off Road ?

New to site.  Like to get some advice.  Read on here that one should not use K & N filter for off road.  What would be the problem?  I have not installed it at this time.  What do you guys think?

Some complain about the mesh/filter being to open allowing small dust particles to enter the air box...not seen any proof myself

Have heard K&N air filters use cotton gauze in there filters which allow dust particles too seep through, I am sure some riders on here use them with no ill effects that can tell you more about them! I use twin air and OEM foam filters there cheap enough and easy to clean and re-oil!

1) goto shop
2) find K&N filter
3) open box
4) walk out the shop with filter in hand
5) hold filter towards the sun
6) see a little bit of light through the filter
7) convince yourself you see a little bit of light through the filter
8.) amaze yourself you see a little bit of light through the filter!
9) realize what this means!!!
10) walk back into store
11) put filter back in box
12) put box back in rack
13) thank dog you have pals on the forum

That's 13 actions, if ignored or not understood - buy it, put it in and shut up forever, and don't even think of coming back here crying sorrow!
Fwiw, Europe* does not have real dust, this is only found in arid rocky terrains, so the negative effect of a K&N (in fact any cotton gauze filter!) will last longer to display itself.


(* perhaps inland Spain but nowhere else)

Fwiw:

- a paper filter filters best, period!
- second is an oiled open-cell foam filter.
- a cotton gauze filter filters least.

- a paper filter flows very good when clean but clogs up quickest and is not cleanable. It also is quite cheap so most cars have this type as OEM.
- a foam filter flows a bit more than paper whilst if filters quite well, and it is surprisingly (read: astonishingly!) resilient in flowing air even when caked with soil/debris. It also is cleanable hence reusable, and it is no coincidence that all offroad bikes come with this type of filter.
- a cotton gauze filter flows hands down most, simply because it filters least (least airflow resistance). At all times they let through fines (fine dust particles) because the filter is not designed to filter these out - at least not when the filter is clean. Dust settling onto the oiled cotton gauze (the filter) acts as a filtering aid (yes, you read that correct) but also as a resistance barrier causing the flow to become less .... ergo, a soiled cg filter filters better but flows less! In some user manuals you will also find this advice however in form of 'do not clean too often' or why. Also, a cg filter does not have the large surface area the other two filters have hence will clog quickest in real offroad environments.

But, don't belive all this, I just am telling nonsense..... ask yourself what type of filter Honda put in?
I know f.all, and you'll agree with me they know best

1 more - are K&N filters rubbish?
No, not at all, in fact I own & use one!
My trackbike has one in, with cat-less race exhaust system plus a PCII to get the fueling right.
All the above mods are aimed to increase gasflow hence performance, and longevity aspects are hardly considered.
But, but... keep in mind it is for the tarred track, hardly any dust there.
All my offroads have foam filters in them, so I do practice as I preach

Thanks for all the great information. I do agree with you all and it makes complete sense. My point of purchasing the K & N mostly was that it creates a seal on the outer edges of the filter against the walls of the Air Box. This will not allow dust to come through if the side cover is not completely sealed and lets in dust.

From the information gained, I will be modifying this application by the following:
Create a pre-filter with K & N's pre-filter sceen at the stock air intake under the seat and place thinner layer of filter foam over the K & N filter to make sure to catch all the dust that may get through. This should create a full proof filter and not restrict flow to much. The K&N filter will not need to be cleaned very often with this extra protection of pre-filters. Once completed I can take pictures if you all like. I think the pre-filter at the air intake would be great for all bikes to assist in catching the larger particales before hitting any filter.

What do you all think?

Get a Twin Air or UniFilter and some good foam filter oil. Use heavy grease around the edges of the filter seal area in the airbox. Good to go. I have the Twin Air with the internal cage and no backfire screen. been running it like that for three years. Works great and absolutely no dust bypassing the filter.

What do I think?

Well, I've always been honest, upfront and assertive, so I think you're bonkers and have lost it!
But, by all means try reinvent the wheel, it is just that the gazillion existing one's proving themselves daily all over on our planet has discouraged me from doing this
But yes, post pics please, I promise I'll giggle

dweller wrote:Get a Twin Air or UniFilter and some good foam filter oil.  Use heavy grease around the edges of the filter seal area in the airbox.  Good to go.  I have the Twin Air with the internal cage and no backfire screen.  been running it like that for three years.  Works great and absolutely no dust bypassing the filter.

I largely agree with you although you probably/surely know there's filter-paste (not really a grease) for sale out there? But whatever, it will work.
No backfire screen I think is not very wise, this after all is a 650... seen the slug going up & down?
Get a screen from XRsOnly, it is waayy more open than Honda's OEM screen which quite frankly is a bit restrictive however will kill flames! Yours clearly will not (duhh..), and as a consequence it may burn/dislocate and next be swallowed - and, out in the remote sticks I would dislike that actually

ok convinced, not a good idea on the K&N for off road.  Going to return the filter.  How do you all make for certain that nothing gets past the cover and around the foam filter.  I just do not think it is a full proof stock system. Will the filter paste around the edges of the foam filter do the job. Have not seen this product before. I will need to go to my local shop and ask for it, I guess.

If you dislike any modding on the filter keep it stock standard, Honda's filter-assy isn't bad by any means!
Both UNI & TwinAir are good filters, they fit well and do the job, in fact I don't use any paste/grease on the edge. The UNI has a moulded rim which fits very well (can't remember the TwinAir's shape).
I do smear the inside of the entire housing (post-filter, up to the carb) with filter oil so that fines bypassing the filter (which any filter will do) will show up.
And, I use XRsOnly's screen, I think it's stainless even.

Went and purchased the Uni air filter and the XR Only screen. Looks like a system I would be comfortable with. Thanks for all the information guys. I should have this installed before my next ride.

Know how to oil a foam filter?

I know, everybody says yes.... and do it wrong.
Here's how!

Take the soiled filter off the frame (so filter only) and add dishwash goo, plenty, on the In- and Outside.
Massage & squeeze (never ever wring!!!!) the filter until the dishwash & dirt & old filter oil are all very (very!) properly mixed, then put the filter down and instantly grab & hug your misses/mistress/GF/partner (one has to remain PC for the few if any fruitcakes present here, ahem ) because your hands will be super-filthy! If you've not done this job yet you dunno what I'm talking about  
Clean all (hands automatically included) under a running tap (lukewarm's best) until you end up with 'all clean', and of course the filter is too because you massage & squeeze it all the time. This means that also the inside of the foam is clean, which of course is what you're after.
Did I mention you never-ever wring a foam filter? NEVER EVER!
Then press-dry the filter, first in the air until all leaking water disappears and then inbetween a spanking clean dishwash cloth.
Put both (cloth & filter) out in the sun/wind to dry.
Once both dry apply your fave filter oil on the in- and outside of the filter and again massage this oil to spread it everywhere, and of course it will be 'too much oil'!
Wash your hands (by now you know dishwash works wonders for this) and then squeeze the filter in the still clean & dry dishwash cloth until it pulls no oil from the filter anymore!
If the dishwash cloth is not soaked with oil you have
- applied the correct amount of filter oil on the filter initially, before you started spreading it,
- a properly not-over-oiled filter ready to put in your bike.
If the cloth is soaked take another and and continue to pull any excess oil out of the filter (and use less oil the next time!).
The idea is to end up with 'a bit' oily foam filter, and if your filter-oil is not coloured it will hardly be visible - which, gents, is the correct amount of oil on/in a filter!

Remember, if dishwash (the mildest detergent around!) cleans the oil & dirt then washing powder (waaaayyyy more agressive than dishwash!) will clean the dishwash-cloths absolute perfectly, and I mention this wrt the boss in the house you live in