I have been using K&N filters in my own motorcycles for 40 + years, & I put high mileage on my motorcycles----I sell in my shop nothing but K&N air filters, & have been doing so for 20 + years. I have never & I Mean NEVER had a single issue with using them-no engine damage, etc. ---NOW I will not use a K&N oil filter on a bet--But I do use the airfilters.--Some will not agree but this is my experience ---& I have a shitload of miles under my belt.

 

I used K&N on my current bike. I know a street rider that does not use an air cleaner at all and it does not smoke. That being said, it's all about the microns entering and scoring lines into the cylinder wall finish. Collect those lines together and you have oil to burn and compression to lose.

Wear out as, I double up the filtering process so as to pre-clean before it hits the main pleats. The meat puppet more explains some of those dickhead squid moves of filtering where the micron meets the road [debris]...

 

At 45k miles my Multistrada 1200 burns some oil - maybe a quart every 3k miles.

I've had a K&N filter in there for the past ~20k miles.

In other motorcycles I've used K&N (or similar) but they've never burned oil like this, even at higher mileage; like that VFR with 104k and FJR with > 90k miles. I had a Ninja 1000 with a K&N but sold it with only 30k, and never consumed oil.

I've seen some articles regarding K&N's poor filtration and never thought much about it ... but now I'm wondering.

What are your experiences?

My VFR has 120k and I’ve used a K&N air filter since the beginning, it still doesn’t burn or drop any oil. It’s had Honda, Fram, Bosch and now K&N oil filters the last 30K or so.

I just noticed my ‘20 1260 had gone down almost 2/3 a quart, in the last 2500 miles since the last oil change, stock oil and air filter and 5k total on the bike. I just changed the oil again and went to K&N oil filter, same K&N I used on my 1200 for 10k and no problem.

 

The alleged issues with K&N air filters are well documented, but as to whether they make that much difference to a street driven/ridden vehicle is up for debate.
I've used them in the past and never had issues and personally think the whole thing is a bit overblown, most likely by other manufacturers trying to sell their supposedly superior product.
Personally I have used MWR air filters for at least the last 10 years with no issues.
One question - how full do you fill your bike with oil? If it's up to the top line maybe drop it back a bit closer to the lower level line and see if it makes a difference.

 

One question - how full do you fill your bike with oil? If it's up to the top line maybe drop it back a bit closer to the lower level line and see if it makes a difference.

I fill to the top line. I've never it go below the bottom line. Seems to be about 1/5 quart between the two.

Why would fill level matter re: consumption? Not saying you're wrong; just curious why it would matter.

never ever use one in a dirty environment like off road racing all they seem to catch is low flying geese.

I only put about 500-1000 miles/year off-pavement, and this bike is too heavy to go off-road.

I would not choose a K&N type for anyone riding dirt roads or off road..... unless they have mice.

check the valve guides next service.

What am I looking for ? wiggle for looseness ? Or a leakdown test?

Somewhat of a unique case, but for my Multistrada 1200, I chose to go with a K&N. After seeing what kinds of crap makes it's way past the awfully designed stock filter / seals, I decided whatever filtering downsides the K&N has, at least it's closed off on the left side and has proper gaskets to seal with the airbox and filter. This should prevent actual large debris from making it's way in, which is what was happening with the stock setup.

I use the DU-1112 - not the DU-1112R which has higher flow, less filtration.

Each time I access the filter I need to vacuum out pebbles and sand etc. from the top of it, and the airbox looked pristine. This last time the filter took quite a bit of effort cleaning all the debris out of the pleats.

I also see no real performance benefit to foam (have never seen a dyno result from a reputable source showing anything more than marginal gain)... so why do it.

Because they're reusable, so I don't have to spend $60/year on the paper filters. In retrospect, if this is the cause of the oil consumption, this is shortsighted. If I manage to fix the oil consumption I might go back to paper.

 

K&N air filters on the street don't seem to be much of an issue when oiled periodically (they dry out) but never ever use one in a dirty environment like off road racing all they seem to catch is low flying geese.

There oil filters have very little pleating with what micron filtration I don't know, most don't have anti drain back valves & use a bimetal spring for bypass control not a coil there basically junk in any application.

It's called 'marketing' bombard media & print sponsor a bunch of racing venues for 40+ years & Walla every body has to have them kinda like that splitfire & E3 spark plug crap or those goofy intake vortex things for increased fuel mileage that fell apart getting digested in engines.

If the media says it's true.....people belive it

Kinda like today's news

 

I see bikes with K&N filters that have dirt that has made it through the filter, same with other performance filters. I also see bikes with K&N (and others) where the airbox is clean. It might be where you ride that puts you at risk more than what filter you use.

I would not choose a K&N type for anyone riding dirt roads or off road..... unless they have mice.

check the valve guides next service.

 

Opinions are like a**holes, everyone has them! But that's what forums are for, right?

I agree that K&N filters are not for off-road use in any capacity. Just like oiled-foam filters aren't really intended for street use. K&N on the street though? I don't prefer them, but also don't think they're necessarily bad depending on use case. I wouldn't use them in a car that sees a lot of mileage.

Somewhat of a unique case, but for my Multistrada 1200, I chose to go with a K&N. After seeing what kinds of crap makes it's way past the awfully designed stock filter / seals, I decided whatever filtering downsides the K&N has, at least it's closed off on the left side and has proper gaskets to seal with the airbox and filter. This should prevent actual large debris from making it's way in, which is what was happening with the stock setup.

So while it's only had the K&N on for the last ~7k miles (since 40k), I don't burn a drop.

 

I used to use K&N on my cars and didn't have any problems... but after reading the research regarding the actual performance of foam vs oem paper (oem are 10-100x better at removing particles - which is what they're there to do) I stopped using them. While oem performance may just be overkill, I also see no real performance benefit to foam (have never seen a dyno result from a reputable source showing anything more than marginal gain)... so why do it.

 

My ST-2 has never been modded, runs OEM filters, 46,000km, and uses about 80-90 cc / 1000km
My old 900SS which was a dog when I bought it, had a K&N square filter, 62,000km, and used oil like a 2-stroke
My 916/996 get so little use it's not a concern, shelf life is moreso!

I've run K&N´s in the past on other race machines etc but they were never together long enough for it to be a worry power was no.1

I guess it depends what you're looking for and how much engine life you want. For my ST2 I want a very long engine life so t gets a new oem oil filter & oil change every 5000 km and a new oem air filter every 12,000km - the box stays very nice and clean so I don't suspect the oil consumption is down to bore wear.

I also have a totally standard well FSH 2004 Alfa 156 2.5 VS with almost 200,000k on it and until about 20,000k ago it hardly burnt a drop, that'´s changing now still bugger all in the big picture though, I suspect it's the guide seals

 

K&N are the worst filter on the market for actually filtering the dust particles out. The only scenario worse is no filter at all. I have first hand experience with them. That said, they are great for max power while keeping the big chunks of stuff out like in racing situations. I’ll never buy another original-design gauze filter of any brand.

You may get by using them with no issues, but the design was/is faulty for long-term filtering. Short term racing is fine.

To keep their business alive, K&N purchased AEM filters and market synthetic filter materials that are better than K&N in all measures.

 

"What am I looking for ? wiggle for looseness ? "

Yes wiggle the valve with no closer first in the NON- thrust direction and then in the thrust direction. This will allow you to feel how much wear you have . Another test would be a tailpipe gas test as high HC will be oil getting by.

Engine braking with loose guides drinks oil like you are using a straw, simply do not engine brake from high rpms and you can reduce guide consumption.

 

Engine braking with loose guides drinks oil like you are using a straw, simply do not engine brake from high rpms and you can reduce guide consumption.

That's an interesting comment - next time I ride I'll pay more attention to whether I do that.

 

At 45k miles my Multistrada 1200 burns some oil - maybe a quart every 3k miles.

I've had a K&N filter in there for the past ~20k miles.

In other motorcycles I've used K&N (or similar) but they've never burned oil like this, even at higher mileage; like that VFR with 104k and FJR with > 90k miles. I had a Ninja 1000 with a K&N but sold it with only 30k, and never consumed oil.

I've seen some articles regarding K&N's poor filtration and never thought much about it ... but now I'm wondering.

What are your experiences?

Oiled K&N covered by oiled foam, a layer of Kotex pads (new) sprayed with cooking oil, all held together by a sleeve of used panty hose. Kills horsepower, but boy, does it filter.
Pilgrim

 

OK this does not address the oil consumption issue--I think that has been discussed, But I race a 1972 BMW R75/5 in AHRMA, the engine is built and she always does really well. --Years ago I ran it with velocity stacks, then I moved to Florida where sand is everywhere. I didnt want to get sand in the engine so I went with K&N pod filters--I did dyno it with the stacks on & then with the K&N pods on---There was absolutely zero difference in power on the dyno, which actually surprised me.

 

I need a dyno...!!!!

 

I have use k&n air filter on everything for roughly 25+ years, everything. The only things that have consumed oil over all that time are an old Jeep which many would have given up long before I even considered doing so and a new and now pushing 150k miles Subaru. I assume they all do because of the horizontal design.

 

Your bike is sucking air like E. The shortest path and all that; wash that valve stem on the intake stroke. Ring cleans up cylinder walls with that squeegee effect, you burned off oil you can't see burn as smoke, but it's lowering the oil level as it runs.

Who's smoking, rings or guides?:
Ring: It's the constant mist you can see as it runs and does not stop.
Guides: The lift and that sustained pulling oil out every stroke, you throttle up, and a bellow of smoke starts and ends as you accelerate away.

But notice how the lift kept the strokes at bay until the throttle up? Shows the guides leaking at every intake stroke be the invisible smoke.

 

At 45k miles my Multistrada 1200 burns some oil - maybe a quart every 3k miles. I've had a K&N filter in there for the past ~20k miles. In other motorcycles I've used K&N (or similar) but they've never burned oil like this, even at higher mileage; like that VFR with 104k and FJR with > 90k miles. I had a Ninja 1000 with a K&N but sold it with only 30k, and never consumed oil. I've seen some articles regarding K&N's poor filtration and never thought much about it ... but now I'm wondering. What are your experiences?

K&N is actually not owned by the original people. As like every US company they soils to. Chinese firm. But enough about that, K&N has a better filtration then paper filters. Myself I use them, well use to I switched over to another brand on my other Italian but still using K&N on my Duc all because of the 1” hex. Switch brands if that doesn’t work out try a different oil & change viscosity if oil brand doesn’t help. Originally engines were designed to use about a qt of oil but the new engines, no not as much or if any. Is there visible oil smoke out of the pipe(s)? Also make sure there is no obstructions in any breather line.

 

Is there visible oil smoke out of the pipe(s)?

Nope.

 

I think i figured it out - and I'm pretty sure it was the K&N filter.

I removed it to service it, and saw this:

Note the path of dirt ingress past the edges of the filter. Clearly the K&N is not fitting properly against the airbox!!! Who knows how much dirt has passed through there and into my cylinders. GRRRRR!

Dry-fitting the filter into the airbox is a tight fit, so much that it bows the filter inwards, lifting the middle - like this:

SO ----K&N goes in the trash, time to order a new OEM filter, and decide if I'm up for an engine rebuild.

 

Everyone knows those things are trash

 

Is there a reusable filter you'd recommend ?

 

If properly maintained Twin air foam filters stop everything

Meaning using the correct cleaner, oil, amount of oil & sealing grease.

Here's the twist I really doubt they make a filter for any Ducati so my suggestion is install a paper filter.

 

Cheers Norskie,

I was just about to join the chorus singing the praises of K&N airfilters, since I also have used one for the last 21 years on two Honda Blackbirds (CBR1100XX) - 54k KMs on the first bird, then 130k KMs on the second (same filter removed and installed because I'm a tightarse).

Absolutely no dust ever got past, but I fitted them and greased the seals every filter service.

At 21 yrs old the K&N filter body was beginning to swell though, but the Honda airbox design was excellent and the lid always pressed the filter firmly and correctly into place.

So your issue is the 💩 crap Ducati airbox design or deformation of the fitting ring due heat/damage at removal for servicing.

My current bike, a V4S Multi, also has a 💩crap airbox lid design - more like a thought bubble after a pizza & red wine lunch than an engineered solution. It has a steel ring base on a rubber cap and it absolutely cannot be removed for cleaning without dropping the whole front end out of the V4MS - so some genius thought up the crushable rubber cap and cable ties are used around the fork leg to to crush the lid open enough to slip a filter in/out......it works but it is rough!

No ram air ducts, no sir, just a hole facing the back of the radar in the beak, to suck as much dust in as possible. And this is Ducati's idea of a dirt road adventure bike 😱. Lucky I use it only for bitumen road sport touring 😁.

I am running the paper OEM filter but am considering a K&N next time, though one factor I have to juggle is my decat with stock ecu....don't want to much change in airflow 😉.

I doubt there is a universal case against K&N style oiled media filters - more likely it's down to inferior airbox design. The other airbox I used a K&N in was in a KTM 1290GT - like the Honda, it was properly designed to hold any filter firmly in place........and K&N was a KTM genuine accessory part.

BTW, I was gobsmacked at the amount of dust and bug debris sitting on the airbox rim under the crushable lid of the V4S.....I now know to blow that clean somehow, before crushing the rubber lid and removing the current paper filter.....if it is possible....there's not a lot of access.....might have to disassemble the nose cowls to get in there......😠

PS.....at 45k miles, your valve guides and seals might be worn too. V2's suck hard. Also, not mentioned is type of oil used.....the stronger FS Esther & double Esther blends can cause glazing in the cylinder bores which will let oil slip past the scavenger rings and burn off, so that may be a factor rather than the airfilter.....I doubt that oil consumption will reduce just by changing a filter, but certainly stopping dust is a priority 👍.

 

the Honda airbox design was excellent and the lid always pressed the filter firmly and correctly into place.

So your issue is the 💩 crap Ducati airbox design or deformation of the fitting ring due heat/damage at removal for servicing.

Hi Dave, Thanks for recognizing that I'm not complaining about the filter media, but how the filter seals against the airbox.

I've used K&N (and other brands) in many other non-Ducati applications in the past where the design has a groove and gasket in the filter surround, which fits into a groove in the airbox. Honda, Kawasaki, Yamaha, Subaru, GM, Trumph etc all do this, and it allows for significant manufacturing tolerances and there is no leak between the filter and the airbox. However, Yes, I agree with you, Ducati's design makes it particularly crucial that the filter surround be very specifically manufactured to tolerances or it will leak. Apparently K&N isn't up to that in this application.

And yes I too have learned to have a vacuum ready to suck pebbles rocks insects etc off the top of the air filter when I open it. Here's what the filter looked like, and what came out after tapping it on my workbench upside down:

Regarding valve stems: I've got 57k on it now, probably won't do a desmo until next winter and then I'll check them.

Regarding oil: I've used Motul, Liquimoly, and most recently mobil-1 with no change in oil consumption.

It's not so bad that I need to do something; adding a quart between changes isn't a big deal.

 

Foam filters don’t filter as well as oem paper even when they’re perfectly maintained (and they often aren’t), that’s well understood. What is not as well understood is how risky that really is… I use paper on higher mileage motors and foam on motors I don’t expect to go as long between rebuilds.

 

No, it is clearly not well understood, it is just something that is frequently repeated. They both provide the same level of filtering, one does it with less reduction in air-flow then the other. This is not religion or superstition so you do not have to believe me or anybody else. The scientific experiments needed to prove it to and for yourself are simple and cheap so if it is important to you, go and actually do them and prove it for yourself instead of repeating the nonsense being pushed by people who sell disposable filters.

 

Put a bright light behind a K&N & look at all the pretty holes in the gauze

All those things stop is low flying geese

 

Last time I checked, the risk of engine damage being caused by light getting past my air filter was pretty low.

 

I was talking about the holes allowing dirt through not light

 

That might be what you intended to say but, sadly, it is not what you typed.
If you want to measure how much dirt is allowed or blocked by a filter, then you will have to try to pass some dirt through the filter, not some light. It is a simple enough test to do and at the end of it, you will actually know for yourself what the truth is instead of just repeating the noise of whoever shouts loudest.

 

To each his own

 

Well, no. As I said before, this is not religion or superstition where you can hold nonsensical beliefs and still demand they be respected, this is simple and verifiable physics. You do not need to trust the word of anybody else, not even me, because you can do the experiments and prove the truth for yourself. Light can pass through a hole 400 nanometers (0.4micron) in diameter. For scale, a human hair is 80,000 to 100,000 nanometers in diameter, so no, being able to shine a bright light through the medium does not mean dust or dirt can get through. The sort of dust you want to filter runs between 1000 and 40000 nanometers (1 to 40 microns) in size, with the worst damage being done by particles in the 5-20 micron range. There is a difference between the performance of OEM filters and K&N filters but you would need much more expensive equipment then I have access to to be able to measure it.

 

gauze type filters are not meant for dirt bikes or any bike in a high dust environment
they are meant for street bikes where their higher air flow can increase power output

oiled foam type filters with sealing grease are used in dusty conditions and are superior to paper but need constant cleaning and reoiling

paper filters are best for street use and provide better filtration than gauze but less flow

right ?

 

I would agree with this. Too bad it takes two hours to replace the MTS air filter.

Theoretically the gauze filters should flow better but my butt dyno has never noticed any difference in power output. But my wallet has, vs. spending $60 on a new paper filter each year. I think I'm just going to have to accept that it's the cost of Ducati ownership.