Replacement Air Filter - K&N Without ECU Flash?

[GuybrushThreepwood]

Realized I've had my bike for a while and I've never replaced the air filter. Bought a K&N filter and now I'm kinda regretting it. I saw a lot of people saying that they aren't very good because they don't stop small particulates and that if I install one, I need to do an ECU flash so I don't run too lean. 

So what's the verdict? Should I just install it and stop worrying? Or should I eat the cost, toss it aside, buy an OEM filter and move on with my life?

[CarGuy7a]

There is absolutely nothing wrong with K&N filters. I've ran one on my 2016 FZ with 0 problems ever since it was showroom new. Just gotta keep the maintenance on them, clean and oiled. Where you may run into problems is in extremely dusty conditions which on road you'll likely never see, or if you never oil the filter. If you are just installing the filter and no other addons IE full exhaust system or removing the snorkel off the lid you should be fine tuning wise, it may run a little leaner but I wouldn't think it would be drastic enough to do a flash or tune. Once you start opening up the flow ( removing snorkel adding full exhaust etc) then you would want to retune.

[Shyan]

Just now, GuybrushThreepwood said:

Realized I've had my bike for a while and I've never replaced the air filter. Bought a K&N filter and now I'm kinda regretting it. I saw a lot of people saying that they aren't very good because they don't stop small particulates and that if I install one, I need to do an ECU flash so I don't run too lean. 

So what's the verdict? Should I just install it and stop worrying? Or should I eat the cost, toss it aside, buy an OEM filter and move on with my life?

Nope. K&N is just increase air flow intake into your engine. It wont cost your engine running lean. If you change your original exhaust, it will required to have a proper CO2 adjustment.. I dont know how other country practice but in my country (Malaysia) we can go to local dealer and asking them to have a proper Co2 adjustment for our bike.. Btw I used to have 1 2017 MT07 and now riding 2019  MT07.. both can done the adjustment without any issue in the dealer.

[Triple Jim]

If I hold a K&N filter up to a bright light, I can see light through pinhole sized openings.  Fine dirt can get through those openings.  It's not going to destroy an engine in 100 miles, but I'd rather have a more effective filter.

[GuybrushThreepwood]

5 hours ago, CarGuy7a said:

There is absolutely nothing wrong with K&N filters. I've ran one on my 2016 FZ with 0 problems ever since it was showroom new. Just gotta keep the maintenance on them, clean and oiled. Where you may run into problems is in extremely dusty conditions which on road you'll likely never see, or if you never oil the filter. If you are just installing the filter and no other addons IE full exhaust system or removing the snorkel off the lid you should be fine tuning wise, it may run a little leaner but I wouldn't think it would be drastic enough to do a flash or tune. Once you start opening up the flow ( removing snorkel adding full exhaust etc) then you would want to retune.

And these filters come pre-oiled right?

[GuybrushThreepwood]

Just now, Triple Jim said:

If I hold a K&N filter up to a bright light, I can see light through pinhole sized openings.  Fine dirt can get through those openings.  It's not going to destroy an engine in 100 miles, but I'd rather have a more effective filter.

Is that with the oil applied or no? I thought the point of the oil that's applied to the filter is there to catch the smaller particulates? 

[Triple Jim]

When I used K&N filters I kept them oiled.  The trouble is that if there's a pinhole sized opening in the filter, oil isn't going to fill that hole and stop particles.

When I worked in the nuclear industry, in the area of decontamination, HEPA filters were often involved.  One of the things I learned is that as filters get dirty, they tend to restrict air flow more, and they become more efficient at trapping dirt, not less.  At some point you need to change or clean the filter because it restricts flow too much, but it will be its best at filtering just before you clean or replace it. 

If you think about it, it makes sense.  Trapped dirt tends to fill the microscopic openings in a filter.  That dirt doesn't go anywhere since it's trapped in the filter, but it makes it harder for subsequent dirt to get through.

[GuybrushThreepwood]

Just now, Triple Jim said:

When I used K&N filters I kept them oiled.  The trouble is that if there's a pinhole sized opening in the filter, oil isn't going to fill that hole and stop particles.

When I worked in the nuclear industry, in the area of decontamination, HEPA filters were often involved.  One of the things I learned is that as filters get dirty, they tend to restrict air flow more, and they become more efficient at trapping dirt, not less.  At some point you need to change or clean the filter because it restricts flow too much, but it will be its best at filtering just before you clean or replace it. 

If you think about it, it makes sense.  Trapped dirt tends to fill the microscopic openings in a filter.  That dirt doesn't go anywhere since it's trapped in the filter, but it makes it harder for subsequent dirt to get through.

So what do you think, should I go with the K&N or ditch it for OEM? So many mixed opinions on the subject!

[Triple Jim]

That's the trouble with asking a subjective question on a forum.    You have the information now... you should decide.

[GuybrushThreepwood]

Guess I'll ditch the K&N and just get a stock filter. Why risk it?

[FZ not MT]

On 3/11/2022 at 7:44 PM, GuybrushThreepwood said:

Guess I'll ditch the K&N and just get a stock filter. Why risk it?

My $0.02 FWIW...

There is nothing wrong with K&N filters regardless what folks may say. Look at it logically, K&N has been in business a long time (52 years), and have gained a very good reputation with all kind of vehicles. There is a fine balance between airflow and air filtration. Are there filters that are better at filtering than K&N - most assuredly. With K&N you get better airflow and cleanability which is a big draw to folks. Will it kill your engine from what gets through the filter, not likely in the time most people own their bikes, if at all.

Here's where we get to the tricky part, will the K&N or any other commercial aftermarket filter (non-race) make a performance difference with your FZ/MT? According to 2WDW the answer is no. They did some testing with several filters for the FZ/MT some years ago, and the results indicated no practical performance difference (it's somewhere in this forum, you do the digging or call them). I've used K&N filters on both cars and bike with no known issues, but decided to go with the MWR for my bike. I have around 8-10K miles on it with no known problems. My bike has a stock exhaust with the snorkel removed and the MWR installed, and a 2WDW flash. I orginally used the stock filter after the flash, but hated the suck sound of the air inlet after the snorkel was removed. I switched to the MWR and never looked back as it sounds pretty badass IMHO, plus it's cleanable. I couldn't be happier with this setup, so much so, that I have no desire to mess with my engine any more for fear of screwing up how good it is now - if you knew me, that's a hell of a statement because I always tweak anything I own that is tweakable

My $0.02 FWIW (part 2)... keep your K&N. You made an investment in that K&N, and I wouldn't second guess it as it will work well for you - No filter is perfect.

Of course, you could sell it as a lot of people would readily buy it at a discount, and get something else like a MWR, UNI, DNA, etc.

If you decide to try something else, here's a link to the MWR which I highly recommend, plus they give forum members a discount:

https://www.bellissimoto.com/parts/air-filters/mwr-performance-air-filter-for-the-yamaha-fz-07-mt07-tracer-700-xsr700-and-tenere-700

 

Edited March 14, 2022 by FZ not MT

[cornerslider]

I 100% agree with the above post ^^^^ . As long you retain the OEM airbox, and use an OEM "style" K&N filter, you won't harm a thing. K&N filters are the best in the business (in my personal opinion). I have them in all four of my bikes, as well as both my car, and truck. Once you buy the cleaning kit, they can be used over and over for the life of the vehicle. I think K&N has a "million mile warranty" on all their air filters-

[MMace28]

I personally got the DNA air filter without the stage 2 cover. I then 3d printed the cover, didn't want to pay 90 bucks for some plastic. Flash tuned by 2WDW, haven't even got to ride it yet after the flash due to weather. But from looking at both filters, dyno charts, etc. unless you're chasing HP goals or go off roading with the bike it shouldn't be a big deal of what you got. I had a K&N on my NA Miata and it did its job, eventually upgraded it just to upgrade.

[FZ not MT]

On 3/19/2022 at 8:45 AM, MMace28 said:

eventually upgraded it just to upgrade

WOW, do I totally understand that comment