K&N air filters

[DUCAUDI]

I think the evidence out there and general consensus is that an 'upgraded' air filter will increase air flow. Reality being you'll probably need an exhaust upgrade and a remap to get any proper BHP gains and even then it probably won't be noticeable. But some like K&N from an economic point of view (supposedly lasting the lifetime of the vehicle).

I'm a lazy shit though. No way I'm ever going to clean the filter, wait for it to dry, clean again, wait for it to dry, then re-apply oil before re-fitting the filter again. Plus I'd be paranoid about either applying too little or too much oil. Personally I'd just rather treat even the K&N's as disposable and buy new every time.

Question is - how often is it recommended they're cleaned/replaced? I can't find the answer to this on their website. Also I think I heard somewhere they clog up quicker than OEM filters (often resulting in REDUCED performance) so just doing it every service probably isn't sufficient?
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2023 DucAudi Mehrstraße V4 Hechte Gipfel - "Objectively the best motorcycle ever produced" - "You can have any colour, as long as it's red"
2021 Honda CMX500 Rebel S

[jeffyjeff]

I believe standard practice is to clean the K&N filter at the same interval that the manufacturer recommends for OE filter replacement. Of course, most manufacturers add the folloing caveat: "riding in dusty conditions will require service intervals to be reduced".
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History shows again and again how nature points out the folly of men - BOC

[davebike]

Unless you looking for performance I would not use K&N in course of work I cleaned thousands nasty dirty job and they do not filter as well as paper filters
To clean you use their solvent blow-dry put on heater leave to dry more add their oil their oil and solvent is not cheap
I have one in my Grom but it may well go
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Dave
NC750Xdct + others at work !
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[RhynoCZ]

Yes, a K&N filter will increase the air flow, but why it's that? Well, it's because those K&N filters don't filter the air that well.

I wouldn't bother with K&N filters. Those power gains are mesureable maybe on a race track (where running no filtration at all would be ideal) and in a laboratory.

Also, let's say you do use K&N filter and you do remap the system (to prevent lean mixture), if the stock engine does 100kW you will not notice it doing 102kW on the open road. You could however notice premature wear in the combustion chamber/s and head valves.

IF you want a cheap performance boost, change the final drive gear ratio. Loose on tooth front or add 2-3 teeth back and this will make your bike way quicker than a K&N filter. The top speed might get even higher, as on most of motorcycles (cars) the top gear is over drive = the engine struggling to spull it up.
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'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[yen_powell]

The one I had had a huge mileage before cleaning was recommended by K&N. That one did about 150,000 miles in two separate bikes.

It was a bit of a soak in the K&N gear, let it dry then use an aerosol to spray a thin layer of oil over it.
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Blackmail is a nasty word........but not as nasty as phlegm!
XT1200Z and a DR350 in bits

[xX-Alex-Xx]

Only advantage with K&N filters is that you can reuse them. But considering how often you change a filter and how cheap paper ones are compared to a reusable one, unless you're covering serious mileage a lot of the time, it's cheaper and easier to just stick with paper filters.

I've used em previously on my GXSR1000 and CBR600, but CBA to bother with them now. Easier to just to swap in a new filter and call it a day.
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DILLIGAF

[Kawasaki Jimbo]

50,000 miles!
https://www.knfilters.co.uk/blog/how-much-kn-air-filter-cleaner-do-you-need-to-use-to-clean-a-kn-air-filter/

I’ve got K&Ns in both bikes, one stock and one with a DynoJet Stage 1 tune (carb needles and a Remus can). On the Kawasaki I’ve cleaned and re-oiled it once in 60k miles although it may have been gently tapped /blown/vacuumed in some services. It’s almost fit and forget.

[Fizzer Thou]

[DUCAUDI]

[Pigeon]

I bought K&N purely on the basis that they were an upgrade. For both SV650 and 675.

Have since read something which seemed to indicate they just filter less. Larger particles were going into the engine.

On that basis, I switched to BMC a couple of years ago. Which just seemed to be better made. Plus the actual filter area was larger than the K&N.

I've noticed no difference, but just prefer the build of the BMC.

[chickenstrip]

Got a BMC filter in mine, which I think is a similar thing to the washable K&Ns. Put in to go with the Ivans carb mods, and part of the airbox cut away to further increase airflow. I have never given it much thought since this was done, cleaned at service time, this filter has served for 10s of thousands of miles, no problems encountered.
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