Topic: K&N "High-Performance" Air Filter

[Kaze]

It's time to buy another air filter. I've always used whatever was available at the shop, which in most cases was Emgo. I'm probably just going to get another "cardboard" type filter this time too, but I was wondering if anybody liked the reusable K&N filters? From my limited knowledge of filters, it seems like one of those "good on paper, not in practice" type ideas.

I'd especially appreciate any opinions from folks who have actually tried one of these, or use one currently.

https://www.jegs.com/i/K%26N/599/HA-0100/10002/-1?gad_source=4

[rotortiller]

They are good so long as they are oiled properly. The K&N filter media is actually good enough to be used for aircraft air filters and they are cleanable/reusable, a virtue just like with Unis. I have one K&N on a Kawasaki triple that works fine. Also have Emgo and Unis OEM shaped air filters on various street bikes with no issue. Oil laden air foam filters are common on dirt bikes as they catch all the dirt. I have an oiled foam air filter on my R6 that works great. K&N is just a different way of filtering, so follow the directions and it will be fine on a street bike. Filters I would stay away from for a CB750 would be the pod types.

[Alan F.]

That's not a bad price for the last air filter you'll ever need.
I picked one up on ebay a few years back for $55 and thought that was a very good deal. I wonder how their shipping costs are?

[seanbarney41]

That is all I have ever used on my cb750's...except for the anti-pod (foam) and a HA breadbox with UNI foam filtration.  Granted, SW Michigan where I do most of my riding is not very dusty, as long as you spend most of your time on the pavement.

[HondaMan]

I've used the K&N in every 750 I've owned or built up. There's nothing like them. When you get one new, it is severely over-oiled, so get the "Cleaning and Oiling" kit, too. It and the filter will still be usable when I'm dust!

When you get it, clean it completely, using the detergent and instructions in the cleaning kit. Let it dry for 1-2 days afterward. Then add just a drop (literally) of oil at the outside of each pleat, or if you get the spray oil, use a fast-pass across only the upper side (half) of the gauze, let it soak down, this will take most of a day.


Then it is good for 25 years, unless you ride more than 10,000 miles per year. I only cleaned and oiled my last one 4 times in 126,000 miles. It shrank at the top after 40+ years and wouldn't fit well in the airbox, so I bought a new one, in 2006. It hasn't been cleaned nor re-oiled since, and doesn't need it, either.

In case you can't tell, I REALLY like these filters...

[RAFster122s]

In our stock air box they work well, the pod filters would require more frequent maintenance given their exposure will make them quicker to load up with dust.

Here in Southern AZ most shops do not recommend the K&N filters or Uni filters because of the high dust conditions we have almost all the time.

[Kaze]

WOW. I did not expect such a resounding positive vote. Thanks guys! I'm glad that I asked. It's a big help.

[Tracksnblades1]

WOW. I did not expect such a resounding positive vote. Thanks guys! I'm glad that I asked. It's a big help.

It’s just like another oil thread.. just tell me what manufacturers install them (K&N) on their products at the factory or will warranty the same on yours. On or off road..

https://www.project200.com.au/dm-iso5011/

Some tests of all that “properly treated dirt”.

It’s like what’s  the best oil? Pennzoil, Quaker State,  or Shell ?
Wonder who owns all 3.?

And another not as scientific as the 5011 test but similar results..

[Kelly E]

Banks Engineering supplied a K&N cone shaped filter with the premium Sidewinder turbocharger kit I installed on my 93' Ford F-250 diesel..

[enwri]

WOW. I did not expect such a resounding positive vote. Thanks guys! I'm glad that I asked. It's a big help.

It’s just like another oil thread.. just tell me what manufacturers install them (K&N) on their products at the factory or will warranty the same on yours. On or off road..

https://www.project200.com.au/dm-iso5011/

Some tests of all that “properly treated dirt”.

It’s like what’s  the best oil? Pennzoil, Quaker State,  or Shell ?
Wonder who owns all 3.?

And another not as scientific as the 5011 test but similar results..

I always thought K&N used to be popular because they flowed better for racing applications, and wear was just an accepted result from increased performance with engines being rebuilt regularly anyway.
Better than open stacks with stone screens, and still being able to breathe when covered in dirt.
 
Screwing everything out of most engines rarely results in long life and reliability but people do it anyway. It's just whether the performance gain is worth any negatives.

So unless you're riding near or through deserts, (Silica dust especially) the amount of contamination you'll pick up in your area could be low to start with so any extra wear may be negligible.
So will any performance gain, but it'll be there .

Can reuse them forever so that's a positive.

[PeWe]

I have searched for alternative filters for my Mikuni TMR32 carbs.
Only K&N that make filters that fit. Pod filters.

I looked for Weber dual port filters that might fit. Again only K&N.

Same for my Mikuni VM29. They have K&N pods too.
My CB750 K2 has K&N filter in stock airbox.

Modern bikes have other filter maker alternatives.

When Im riding my K6 with pod filter I look for sudden dusty winds.  Typical in springs after winter when meeting a heavy vehicle as a truck or buss. Throttle off, clutch lever in and keep on rolling to clean air.

I have killed engine once after acceleration before rolling thru a local dust storm. Dry soil.
Kill switch on when thru and released the clutch lever to start it still rolling.

I trust the filter, just not want to make them dirty and need to clean them.

I rode 2 rides in November 2022 that made pod filters dirty. Wet slimy roads with thin sand like material. I got thoughts about volcanic ash.
Cleaned the pods again. They were cleaned only a month before.

The entire bike was covered by the dirt

[Tracksnblades1]

WOW. I did not expect such a resounding positive vote. Thanks guys! I'm glad that I asked. It's a big help.

It’s just like another oil thread.. just tell me what manufacturers install them (K&N) on their products at the factory or will warranty the same on yours. On or off road..

https://www.project200.com.au/dm-iso5011/

Some tests of all that “properly treated dirt”.

It’s like what’s  the best oil? Pennzoil, Quaker State,  or Shell ?
Wonder who owns all 3.?

And another not as scientific as the 5011 test but similar results..

I always thought K&N used to be popular because they flowed better for racing applications, and wear was just an accepted result from increased performance with engines being rebuilt regularly anyway.
Better than open stacks with stone screens, and still being able to breathe when covered in dirt.
 
Screwing everything out of most engines rarely results in long life and reliability but people do it anyway. It's just whether the performance gain is worth any negatives.

So unless you're riding near or through deserts, (Silica dust especially) the amount of contamination you'll pick up in your area could be low to start with so any extra wear may be negligible.
So will any performance gain, but it'll be there .

Can reuse them forever so that's a positive.

You would like BT Barnum and Mark Twain. They have some quotes  that follow your assessments..

[Don R]

 Has anyone else tried a K&N in a K0 airbox? They don't fit mine very well at all. I've never bought a new one, but they came in a couple bikes I've owned.

[HondaMan]

I have killed engine once after acceleration before rolling thru a local dust storm. Dry soil.

In 1977 my brother and I met in Texas in August, then toured the Southwest for several weeks (hint: do this in Spring or Fall, not August...). We were headed north from the Carlsbad Caverns area when we ran into a sandstorm out of the west. We decided to ride thru it, but when we got out of it both of our Vetter windshields were opaque down the left side (about 6" across the front from the left) and the bikes were running poorly. He had the Honda paper filter, I had my first K&N, in the airboxes. We stopped in the next town for the night, pulled out the air filters, and I washed mine out from the inside in the motel's sink and let it dry overnight. My brother had to run without a filter until we got to Albuquerque where the Honda shop had one for his CB500 SOHC4. His bike fouled the plugs about 50 miles after he removed the filter, so he was running on my spare set of X24ES-U by then.

The moral of this story became: use K&N filters when touring in remote areas. They are easy to renew out on the road.

[HondaMan]

Has anyone else tried a K&N in a K0 airbox? They don't fit mine very well at all. I've never bought a new one, but they came in a couple bikes I've owned.

They are a TIGHT fit in the K0 box. I stretched one out lengthwise, using a long nut and 2 pieces of Allthread rod, pushing against 2 little wood dowels (with a hole drilled halfway thru to seat the rods), to stretch it lengthwise. It then fit on width-wise. It took overnight to 'set' the stretch. It was still snug to get on: that was many, many moons ago!

[scottly]

I only cleaned and oiled my last one 4 times in 126,000 miles. It shrank at the top after 40+ years and wouldn't fit well in the airbox, so I bought a new one, in 2006.

Mark, K&N warrantied the filters for 1 million miles, and would have replaced it for free.

[newday777]

I only cleaned and oiled my last one 4 times in 126,000 miles. It shrank at the top after 40+ years and wouldn't fit well in the airbox, so I bought a new one, in 2006.

Mark, K&N warrantied the filters for 1 million miles, and would have replaced it for free.

But.....K&N has discontinued the filter for the 750.... so the Would have is the key word....

[Deltarider]

I recommend the genuine Honda filters. They do not restrict, filter way better than foam and can be serviced within seconds. A filterexpert informed me that when airfilter A filters out 99,8 % of the particles and airfilter B 99%, enginewear with B will be fourfold.
If foam filters would be better, Honda would have chosen them.
Foam filters may do fine on lawnmowers.
Some may find it hard to believe, but as a matter of fact, paper filters get better in use. For this and more info: http://forums.sohc4.net/index.php?topic=98901.msg1102737#msg1102737
Can't believe so many favour aftermarket filters which are already inferior fom the start. On a CB500 Four, I can change my airfilterelement within 12 seconds and that includes opening the seat, removing the tooltray, etc. And time, my friends, is the only thing I cannot make extra of. So why would I spend precious time on oiling, getting my hands dirty and then have to worry: did I oil too much, too little?

[MauiK3]

I tend to stick to stock stuff like air filters whenever I can, few exceptions. I'm sure there are other good choices like K&N but I just like to stick with the stock stuff.

[rotortiller]

I kind of like the Emgo paper OEM type airbox filters. One thing about some pod filters being exposed is when they get wet washing the bike  will often foul the machine, like running with the choke on lol. Pods bad airbox good 

[HondaMan]

I only cleaned and oiled my last one 4 times in 126,000 miles. It shrank at the top after 40+ years and wouldn't fit well in the airbox, so I bought a new one, in 2006.

Mark, K&N warrantied the filters for 1 million miles, and would have replaced it for free.

But.....K&N has discontinued the filter for the 750.... so the Would have is the key word....

Wow! That's truly bad news...

[PeWe]

K&N has not stock style on their web site. Only pods for CB750.

There are still filters to find by sellers.
I gave my K2 the first K&N filter for stock air box March 2022.
I have no known need today.
Maybe I should look for a filter nearby and order just for sure.

I think it flows air better, can be good as an additional jetting thing.

[Tracksnblades1]

I recommend the genuine Honda filters. They do not restrict, filter way better than foam and can be serviced within seconds. A filterexpert informed me that when airfilter A filters out 99,8 % of the particles and airfilter B 99%, enginewear with B will be fourfold.
If foam filters would be better, Honda would have chosen them.
Foam filters may do fine on lawnmowers.
Some may find it hard to believe, but as a matter of fact, paper filters get better in use. For this and more info: http://forums.sohc4.net/index.php?topic=98901.msg1102737#msg1102737
Can't believe so many favour aftermarket filters which are already inferior fom the start. On a CB500 Four, I can change my airfilterelement within 12 seconds and that includes opening the seat, removing the tooltray, etc. And time, my friends, is the only thing I cannot make extra of. So why would I spend precious time on oiling, getting my hands dirty and then have to worry: did I oil too much, too little?

+1….

Carl Sagan
“One of the saddest lessons of history is this: If we’ve been bamboozled long enough, we tend to reject any evidence of the bamboozle. We’re no longer interested in finding out the truth. The bamboozle has captured us. It’s simply too painful to acknowledge, even to ourselves, that we’ve been taken. Once you give a charlatan power over you, you almost never get it back.”

PT Barnum and Mark Twain both said similar at different times… and it will repeat itself for sure…

[HondaMan]

I only cleaned and oiled my last one 4 times in 126,000 miles. It shrank at the top after 40+ years and wouldn't fit well in the airbox, so I bought a new one, in 2006.

Mark, K&N warrantied the filters for 1 million miles, and would have replaced it for free.

I might go dig it out and try that! I think it's still hanging in the garage somewhere.

[BenelliSEI]

Has anyone else tried a K&N in a K0 airbox? They don't fit mine very well at all. I've never bought a new one, but they came in a couple bikes I've owned.

I have one and found the same thing. It never quite fit right. It did go in my K8 for some reason, so there it stayed. I use OEM.

[RAFster122s]

I think Delta just likes poking a sleeping bear to see what he can stir up...

[Deltarider]

I think Delta just likes poking a sleeping bear to see what he can stir up...

That must be it!!! I now realise it all makes sense. I remember summer 1989, sleeping in a tent in the Californian mountains, we were - in the middle of the night - poked by a bear, grabbing stuff we had left in my backpack outside. As a matter of fact he went off with rucksack and all. At dawn we spotted him nearby and from a distance we awaited the moment he had finished his picknick. There wasn't a molecule of food left but my passport was still unharmed, be it drooled all over.
Now it's my turn to poke a bear.

[jgger]

That was just Yogi, he does love his pik-a-niks!

[RAFster122s]

Do you know in bear country you are told to make noise so you don't startle a bear on the trail of quietly hiking. Many wear small bells for that purpose.
Know how to tell the difference between black bear scat and grizzly bear scat?
There's little bells in the grizzly bear scat.
They are dinner bells to a grizzly bear...

Guess you didn't read the warnings in the park about your food and storing it away from you campsite and often hanging it in a tree from a branch inaccessible to the bears...

[jgger]

Also the scat has a slight pepper odor to it.

[Deltarider]

[...] Guess you didn't read the warnings in the park about your food and storing it away from you campsite and often hanging it in a tree from a branch inaccessible to the bears...

We had read all of them and we knew how to act when we would meet a bear. We had hiked all day and we were tired. Where we camped, was a sign that said 4000 ft. (To be honest I forgot what it said, but I do remember it was a round number). I was tired and - after reading the sign - I wrongly concluded bears wouldn't roam around so high. Now if that isn't a perfect example of cognitive dissonance...
I will never forget the look the bear gave us, after his meal, when he calmly walked away. It said as much as: suckers. The torn backpack with the bears saliva over it, is still in my basement.

[HondaMan]

Do you know in bear country you are told to make noise...

Isn't that what pistols are for?

[Tracksnblades1]

Do you know in bear country you are told to make noise...

Isn't that what pistols are for?

30/06 used to be the smallest caliber recommended for bears…most recommend magnums cartridges that’ll stop a charging bear…

Pistols are known to really piss them off and create a really dangerous situation…

[newday777]

Do you know in bear country you are told to make noise...

Isn't that what pistols are for?

Nope.....
Ask Harry

[ofreen]

Sorry to hear K&N has discontinued the air filter that fits the stock 750 airbox.  Not that I am likely to ever need another one.  I'll include an excerpt from my post back in 2016 below where I talk about why I replaced the first one.  My first one lasted decades.  Whenever a K&N air filter thread pops up, someone will usually chime in that the filters allow harmful particles to pass through.  I don't have any laboratory data to provide, but I have some empirical info.   I have used K&N air filters in all my bikes for years.  They all have high miles.  The filter in the 750F went in at around 10,000 miles.  The bike is now coming up on 169,000 miles and still doesn't smoke or show excessive oil consumption.  I would think that if the K&N filter allowed harmful particles to pass, top end wear would have shown up long ago.  As I have mentioned before in these threads, I have lived at the end of various gravel roads since I bought the bike in 1977.  So am I a sucker?

I installed the K&N air filter in 1980 when the bike had about 10,000 miles on it.  The last time I cleaned it, I noticed the rubber was getting stiff and I had some difficulty reinstalling it.  This time it was hard as a rock, and it would not go into place.  It occurred to me that K&N is still using their million mile warranty slogan, and since the filter was about 850,000 miles short of that, I’d see if they were good for it.  Google turned up their customer service number that connected me to Benjamin.  Benjamin said email me a photo of the filter, the year, make and model of the bike and I’ll send you one.  Two days later I had it in my hand.  It was even pre-oiled.  Thank you Benjamin, you guys are awesome.

[PeWe]

K&N still sell air filter to CB750.
Pods

[BenelliSEI]

Sorry to hear K&N has discontinued the air filter that fits the stock 750 airbox.  Not that I am likely to ever need another one.  I'll include an excerpt from my post back in 2016 below where I talk about why I replaced the first one.  My first one lasted decades.  Whenever a K&N air filter thread pops up, someone will usually chime in that the filters allow harmful particles to pass through.  I don't have any laboratory data to provide, but I have some empirical info.   I have used K&N air filters in all my bikes for years.  They all have high miles.  The filter in the 750F went in at around 10,000 miles.  The bike is now coming up on 169,000 miles and still doesn't smoke or show excessive oil consumption.  I would think that if the K&N filter allowed harmful particles to pass, top end wear would have shown up long ago.  As I have mentioned before in these threads, I have lived at the end of various gravel roads since I bought the bike in 1977.  So am I a sucker?

I installed the K&N air filter in 1980 when the bike had about 10,000 miles on it.  The last time I cleaned it, I noticed the rubber was getting stiff and I had some difficulty reinstalling it.  This time it was hard as a rock, and it would not go into place.  It occurred to me that K&N is still using their million mile warranty slogan, and since the filter was about 850,000 miles short of that, I’d see if they were good for it.  Google turned up their customer service number that connected me to Benjamin.  Benjamin said email me a photo of the filter, the year, make and model of the bike and I’ll send you one.  Two days later I had it in my hand.  It was even pre-oiled.  Thank you Benjamin, you guys are awesome.

Good news! I have one that is as hard as a rock! Will give it a go. Thanks!

[grcamna2]

Sorry to hear K&N has discontinued the air filter that fits the stock 750 airbox.  Not that I am likely to ever need another one.  I'll include an excerpt from my post back in 2016 below where I talk about why I replaced the first one.  My first one lasted decades.  Whenever a K&N air filter thread pops up, someone will usually chime in that the filters allow harmful particles to pass through.  I don't have any laboratory data to provide, but I have some empirical info.   I have used K&N air filters in all my bikes for years.  They all have high miles.  The filter in the 750F went in at around 10,000 miles.  The bike is now coming up on 169,000 miles and still doesn't smoke or show excessive oil consumption.  I would think that if the K&N filter allowed harmful particles to pass, top end wear would have shown up long ago.  As I have mentioned before in these threads, I have lived at the end of various gravel roads since I bought the bike in 1977.  So am I a sucker?

I installed the K&N air filter in 1980 when the bike had about 10,000 miles on it.  The last time I cleaned it, I noticed the rubber was getting stiff and I had some difficulty reinstalling it.  This time it was hard as a rock, and it would not go into place.  It occurred to me that K&N is still using their million mile warranty slogan, and since the filter was about 850,000 miles short of that, I’d see if they were good for it.  Google turned up their customer service number that connected me to Benjamin.  Benjamin said email me a photo of the filter, the year, make and model of the bike and I’ll send you one.  Two days later I had it in my hand.  It was even pre-oiled.  Thank you Benjamin, you guys are awesome.

Good news! I have one that is as hard as a rock! Will give it a go. Thanks!

K&N may just give you a Christmas present