New to k&n filters, have a question

[ridehonda400ex]

So in the last month ive traded my 2001 400ex for a 2001 kx250 2 smoker, loved the bike but was to fast for where i ride at, traded it for a 2005 kx250f with stage 2 hotcams, piped, nice suspension, but it was a ***** to start so i said screw this i love riding not trying to start a stupid bike for 30 mins(yes valves were adjusted) so i sold it for 1500 dollars, bought a 2004 400ex for 1400 dollars. Im NEVER getting rid of it. Its got a K&N filter with the chrome end, it looks sick lol, but my gpa said its a dry filter....i say BS...so i call K&N and they say all automotive filters need oil....should i oil it? Im making a rocky mountain order tonight and will get it

[01boneless]

if its foam it needs oiling but what you descibing is a dry filter and k&n lets in alot of air so i woldent oil it but if you do it shouldent hurt it:)

[ridehonda400ex]

well its the cottony kind, you know what i mean? my gpa said oiling it will clog it up fast, and potentialy ruin it. Which i dont want to bc this filter is nice and no dirt was in the intake boot

[CJM]

needs KN or other paper gauze type filter oil. Personally I HATE them b/c they let all kinds of junk in vs a good foam filter (even the stock one).

But yea, KN filter oil which can be bought at pepboys works, or similar.

[01boneless]

huhh im not sure i know what kind you have if its like this pic below you should oil it if its foam under metal mesh dont oil it cause it is a dry filter :)

[ridehonda400ex]

Boneless-Its the kind with the mesh on top.

CJM- Ive always used uni but right now im not in the mood to do jetting, id rather ride and this filter didnt have any dirt that passed by when i pulled it off soooo looks like ill keep it for now

And i asked the previous owner and he said he always oiled it.

[slightlybent47]

If it’s foam then it needs oil, no mater what the manufacture said. The oil is the main component to a foam filter.
This has been debated to death but one guy that has a dyno did a test with a foam filter and without any filter at all and the deference was less then ¼ hp. So you’re risking motor damage using a K&N and you’re not getting much of a gain at all.
Run what you want but if you want the best protection then go with a stock foam filter with a foam outer filter over that with plenty of foam oil. You’ll be down ¼ hp but you will be protected.

[CJM]

Changing the filter I doubt you will need to mess with the jetting at all. Now if you did an exhaust and the filter-thats another story.

[fearlessfred]

the k and n gets spray on type oil. i would ditch the kn and go for the foam .the very small gain in horsepower is not worth the extra wear on your motor.the inside of yur airboot may be clean right now, but go for a few rides and then check.you can prove it for yourself. it will have a light brown film in the airboot

[Pipeless416]

the information in this thread scares me.. you need this to clean and oil it. after cleaning it with the actual k&n cleaner, i also clean mine off with dish soap in a sink. oil it pretty lightly, because it spreads on its own.

[ridehonda400ex]

i ordered some of that cleaner and oil last night pipeless. how long does it take to dry the k&n filters?

[Pipeless416]

Originally posted by ridehonda400ex
i ordered some of that cleaner and oil last night pipeless. how long does it take to dry the k&n filters?

it really depends. i throw mine up in the air and spin it so it throws a lot of the water out. you should count on at least 2 hours of drying time, sometimes more.

[400exrider707]

It's amazing how much false information gets passed on these boards.

K&N's are all gauze type filters, they all need the oil. If you run a K&N without oil, you might as well take the filter completely off and run it like that. Same thing. Without the oil, it's useless.

I am 100% against K&N's as they can and do let dirt past. I've tried dozens of different oil types (yes including K&N's own), I cleaned/oiled after EVERY SINGLE ride, and there was always a fine mist of dust on the intake boot, no matter what I did.

I finally switched to a UNI, which are 1/2 the cost, and far easier to clean/oil and had 0 problems after. I will never run a K&N on anything except a snowmobile or a car/truck that NEVER leaves the pavement.

If you're just changing the filter, you're probably OK for jetting, but the big question is if you're running the airbox lid or not. What about exhaust?

[Pipeless416]

Originally posted by 400exrider707
It's amazing how much false information gets passed on these boards.

K&N's are all gauze type filters, they all need the oil. If you run a K&N without oil, you might as well take the filter completely off and run it like that. Same thing. Without the oil, it's useless.

I am 100% against K&N's as they can and do let dirt past. I've tried dozens of different oil types (yes including K&N's own), I cleaned/oiled after EVERY SINGLE ride, and there was always a fine mist of dust on the intake boot, no matter what I did.

I finally switched to a UNI, which are 1/2 the cost, and far easier to clean/oil and had 0 problems after. I will never run a K&N on anything except a snowmobile or a car/truck that NEVER leaves the pavement.

If you're just changing the filter, you're probably OK for jetting, but the big question is if you're running the airbox lid or not. What about exhaust?

agree, the whole point of my project to move my battery to the front of my quad is so i can run a UNI.

[ridehonda400ex]

I use the airbox lid and i have an FMF pc4 with no spark arrestor, 406 bore

[DragonGunner]

11 yrs on the same K&N filter, another machine has 7 yrs.....clean by putting in bucket of hot water an DAWN dishsoap, use a scrub brush an rinse with hot water an shake out water...let dry overnight or you can use a hair dryer to speed it up...spray K&n filter oil on as direction on can say, let set for a few hours if possiable. Also buy a Outerwear covering, it cleans in the same way but do not oil it.....carry on.

[400exrider707]

Originally posted by DragonGunner
11 yrs on the same K&N filter, another machine has 7 yrs.....clean by putting in bucket of hot water an DAWN dishsoap, use a scrub brush an rinse with hot water an shake out water...let dry overnight or you can use a hair dryer to speed it up...spray K&n filter oil on as direction on can say, let set for a few hours if possiable. Also buy a Outerwear covering, it cleans in the same way but do not oil it.....carry on.

I used the same cleaning process myself, except I don't think it was DAWN haha. The only way to get dirt to not pass through a K&N, add an outerwear... seems like you shouldn't have to add a filter to your filter though huh?

I still used the full airbox cover/outerwear setup when running my UNI's cause it cut my cleaning ten fold. Much easier to rinse/dry an outerwear than to actually clean/oil a filter.

[DragonGunner]

Originally posted by 400exrider707
I used the same cleaning process myself, except I don't think it was DAWN haha. The only way to get dirt to not pass through a K&N, add an outerwear... seems like you shouldn't have to add a filter to your filter though huh?

I still used the full airbox cover/outerwear setup when running my UNI's cause it cut my cleaning ten fold. Much easier to rinse/dry an outerwear than to actually clean/oil a filter.


I run open airbox, an can usually clean the outerwear several times before cleaning the K&N....outerwear also helps with water as its water repellent....I don't understand if you have a uni why you need a filter cover for a filter.....huh?

[buck440]

Originally posted by ridehonda400ex
trying to start a stupid bike for 30 mins(yes valves were adjusted)

obviously there was a problem if it took a LOT of kicks.

[400exrider707]

Originally posted by DragonGunner
I run open airbox, an can usually clean the outerwear several times before cleaning the K&N....outerwear also helps with water as its water repellent....I don't understand if you have a uni why you need a filter cover for a filter.....huh?

I agree, the outerwear was the ONLY way to prevent dirt from passing the K&N, meaning the K&N wasn't working. I started using the outerwear lid cover (replaces the airbox lid on a stock box) with my UNI just simply because it extended my cleaning intervals. I could race in extremely dusty conditions and not have to change the filter after every race. The UNI never let dirt through with or without the outerwear I just ran it as "extra protection" kind of thing. I was/am meticulous about clean air filters. The outerwear just gave me a little of my sanity back.