K&N air filter. You be the judge.

[liberty2701]

Here is a pic of the intake after my K&N filter on a 1986 xr250. Look at all the fine dust getting through. Yes it is properly oiled and greased. I never believed all the negative talk about K&N filters in fine dust but here is the proof. What got me thinking to check my intake was a test project farm did. I will be switching it to a foam unifilter. 

Edited July 31, 2020 by liberty2701

[69fastback]

K&N filters suck. The end. 

[DEATH_INC.]

45 minutes ago, liberty2701 said:

Here is a pic of the intake after my K&N filter on a 1986 xr250. Look at all the fine dust getting through. Yes it is properly oiled and greased. I never believed all the negative talk about K&N filters in fine dust but here is the proof. What got me thinking to check my intake was a test project farm did. I will be switching it to a foam unifilter. 

Be interesting what K&N have to say about it.

10 minutes ago, 69fastback said:

K&N filters suck. The end. 

I've used them in My old 4WD with no issues (and a couple of roadbikes, though they're hardly a test), and plenty of offroad guys run them with no problems too. Yet every so often We see threads like this. What did you have an issue with? I wonder if it's just certain models, or a quality control issue perhaps.

[The Inquisitor]

IMO the inside of the air box intake doesn't look like it is that dirty for a 1986 bike unless I'm missing something?

I've got a K&N fiber filter in my 03 DRZ400E and clean/oil it with there bio oil regularly and ya I'm not riding it in super dusty conditions but has work's fine.

With that said, if it was me, I'd drop the sub frame, remove the air box and give it a good clean cus I'm guessing that hasn't been done since 1986 but that's just a guess.

Results/opinions will vary

 

Edited July 31, 2020 by filterx

[69fastback]

39 minutes ago, DEATH_INC. said:

Be interesting what K&N have to say about it.

I've used them in My old 4WD with no issues (and a couple of roadbikes, though they're hardly a test), and plenty of offroad guys run them with no problems too. Yet every so often We see threads like this. What did you have an issue with? I wonder if it's just certain models, or a quality control issue perhaps.

I have never ran one on a bike, but the machine shop I used to work for saw it a lot, especially in dirt track cars. Our head machinist could pick out every engine that came in that had been running K&N with almost 100% accuracy. Even with street engines, we would see carburetors with a definite film of dust inside of them. They flow well, and the trade off is that they don’t filter well. He threatened me if I put one on my Mustang. Lol

[SteveThe Snakes]

Ah you should have known better when everyone tells you they suck dirt. They do!

[Rod21]

I ride in Las Vegas super dusty conditions. I'm not worried about it. Very easy filter to maintain. I like it and will clean, oil, and lube regularly.

Better than when I bought the bike where previous owners ran OEM filter without a basket. Baskets were backordered for months and Amazon prime got me running with a K&N within 2 days.

[liberty2701]

28 minutes ago, filterx said:

IMO the inside of the air box intake doesn't look like it is that dirty for a 1986 bike unless I'm missing something?

I've got a K&N fiber filter in my 03 DRZ400E and clean/oil it with there bio oil regularly and ya I'm not riding it in super dusty conditions but has work's fine.

With that said, if it was me, I'd drop the sub frame, remove the air box and give it a good clean cus I'm guessing that hasn't been done since 1986 but that's just a guess.

Results/opinions will vary

 

It is definitely a filter problem. I have two other bikes with factory foam filters without this problem. I also have a UTV with a paper filter which does not leak dust. This area I ride is a very fine powdery dust. I think K&N work for all but the very fine powdery dust 

[turbo dan]

K&N filters try to do what foam filters actually do but the filter media is far too thin to get the job done.

Foam filters hold more oil and will hold more dirt before drying out.  Foam filters are also much thicker, offering no straight through pinholes where dust can pass through without bumping into anything sticky.

[The Inquisitor]

16 minutes ago, liberty2701 said:

It is definitely a filter problem. I have two other bikes with factory foam filters without this problem. I also have a UTV with a paper filter which does not leak dust. This area I ride is a very fine powdery dust. I think K&N work for all but the very fine powdery dust 

Out of interest and as I posted when was the last time you completely cleaned the air box, when was the last time you cleaned the filter, what did you use for a cleaner/oil and how old is the filter?

and yes I can now see a bit a brown dust around the bottom inner edges but I also see a ton of gunk on the outer edges where the air filter seats which makes me think the filter was maybe not seated completely correctly.

And are you also using grease on the filter edge where it meets the air box and if so what type of grease and when was that last cleaned completely ?

Otherwise send your pic with your info to K&N and see what they have to say about this.

Have a nice long weekend

 

[k.g]

K&N filters should not be trusted in any vehicle. 

[The Inquisitor]

3 minutes ago, k.g said:

K&N filters should not be trusted in any vehicle. 

How about Fram or any other type of fiber air filters in any vehicle like cars, trucks etc etc etc or is it just K&N?

 

[Rod21]

1 minute ago, k.g said:

K&N filters should not be trusted in any 

You have any data on that? Did you have bad bad experience with one?

Not asking you to do a science project, but what proof do you have that they can't be trusted.

[liberty2701]

15 minutes ago, filterx said:

Out of interest and as I posted when was the last time you completely cleaned the air box, when was the last time you cleaned the filter, what did you use for a cleaner/oil and how old is the filter?

and yes I can now see a bit a brown dust around the bottom inner edges but I also see a ton of gunk on the outer edges where the air filter seats which makes me think the filter was maybe not seated completely correctly.

And are you also using grease on the filter edge where it meets the air box and if so what type of grease and when was that last cleaned completely ?

Otherwise send your pic with your info to K&N and see what they have to say about this.

Have a nice long weekend

 

It was cleaned before the last ride using a K&N filter kit. I use a green marine grease to seal the edge. Lots of it. Which you can see remnants of. Inside the boot was wiped clean of dust with a rag at the last cleaning. I also forgot to mention there is an Outerwears on the filter.

Edited August 1, 2020 by liberty2701

[Rod21]

1 minute ago, liberty2701 said:

It was cleaned before the last ride using a K&N filter kit. I use a green marine great to seal the edge. Lots of it. Which you can see remnants of. Inside the boot was wiped clean of dust with a rag at the last cleaning.

That filter box and flange looks like a big engineering mistake IMHO, it's going to suck dirt no matter what filter you use.

[The Inquisitor]

4 minutes ago, liberty2701 said:

It was cleaned before the last ride using a K&N filter kit. I use a green marine grease to seal the edge. Lots of it. Which you can see remnants of. Inside the boot was wiped clean of dust with a rag at the last cleaning.

Send your info & pic to K&N and ask them nicely to comment.

Otherwise, get a foam filter, use what ever type of oil you want and see how it works compared to the K&N.

 

[liberty2701]

Just now, filterx said:

Send your info & pic to K&N and ask them nicely to comment.

Otherwise, get a foam filter, use what ever type of oil you want and see how it works compared to the K&N.

 

I ordered a Unifilter with oil.

[69fastback]

10 minutes ago, Rod21 said:

You have any data on that? Did you have bad bad experience with one?

Not asking you to do a science project, but what proof do you have that they can't be trusted.

tons of info for you here, with some factual data  K&N has great marketing and poor filtration, with minimal performance benefits  

 

 

https://pdf.sciencedirectassets.com/282073/1-s2.0-S2212017316X00047/1-s2.0-S2212017316301475/main.pdf?X-Amz-Security-Token=IQoJb3JpZ2luX2VjEIj%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaCXVzLWVhc3QtMSJGMEQCIFc3Q%2F6xoWJEnJR0DZt6bdgIU7PrTimU5JIbctlDFptuAiBJAwgujH1nhOFaEX%2BTr6K8NqJh2pdOvdp9EXHgx5m87Sq0AwhREAMaDDA1OTAwMzU0Njg2NSIMefbrFPqGxdnqAvFkKpEDuCTgY76%2FVTcSFkYAYnoOV4JsqU1XM1DaNvAay6JLUuZ8Pt2d8OmOxvL7cZ9uKyd1MwRlNtqo2S5JNKc3fDG%2BulIU45dwHnHwnFIefx0lPL9w7in7YoECj6%2Fo5sOmhJZupwjiBJAH5O7aXm2tjIDtGxHk0vmA8RCtQFm%2B%2FH%2FURsi9a%2FbvXM3uXEtSNVi4UdqeShFb8WfurKI4WEMhlrKv8e5gCpJEYpdOFqUFmFcxt4M4ULDDGP%2FZgTamy8dHSFAC72%2BjPsyro2C3tBY4lo9jd5B5rVpGtJqnN1Wmk6P3l77JoH28iA8iyBRX3B4KjDfxFu55NPl0q0njNmeayVoZ%2FhxgB9%2FgRGrll%2FsXKdXpllA0ZuYFh15bw7fb5ESZy6kkD%2BB0QiQH3%2BHQcuoNCoJtIUFjMIdhflpPEGd%2BFaQ%2BGd%2F36%2Ffw0EKEM4Zq%2FPo9HOJdhT%2BMns9WvE9hC7w8%2FJGBC0aqqYBkPTFEbYHP%2FDlvLPnm%2F0RhDX7z6gMlA0vlgdo9NHA%2BUsN7vaS7B5%2F%2F1YFkDtcwn92S%2BQU67AF%2F4S7ROMRsyTqDPBQph48dta42VNEWZ9djt7%2BD%2FEt9u9ZjV1RA8AWqjh9q3ow0j0VthrQKhnBSTgw0nfEn3iqDHXsucgzPYg5pwrlKLYxi%2FwxVNJ%2Bt3%2Fa5nkVU4k9dYoPCzVczXJrdhMQtBTAApn%2FIohJ81hQHqP%2BFAWJ%2Fdy9Hdfs18qi9GGNU9%2Bj%2By%2BvvM%2FyuMye6wMjStkUenbNjaf%2FaNEmUwFLtGHbyVqw9e8WkAGFPlm6Q3iHK9Zn4%2BEgo%2BCUXI5%2FoqOEcbx%2FmUZ7S6ywcIEPSjYIdjeCpH8%2BULuLC8WUBA1c871%2FrW9wyDw%3D%3D&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20200801T010338Z&X-Amz-SignedHeaders=host&X-Amz-Expires=300&X-Amz-Credential=ASIAQ3PHCVTYX575NWMP%2F20200801%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Signature=739f49da11efe03c10eb8475dd33b1604df6c28bfdca6f9dbce914ba9f974180&hash=1a4a1cf5fee2987e093485f12d3ffb65053e497af2fae8bd0c575d58689a3636&host=68042c943591013ac2b2430a89b270f6af2c76d8dfd086a07176afe7c76c2c61&pii=S2212017316301475&tid=spdf-275bb632-bd1c-4d9b-af40-95681a52595a&sid=eaae5d9b469f7749995b87d47fc5746b1924gxrqa&type=client

 

 

 

 

Fig 8 shows that the filtering efficiency of the OEM filter was superior to that of the K&N filter. The decreased filtering efficiency of the K&N filter can be attributed to the increased pore size of the cotton gauze medium used in the filter. The actual filtering efficiency of the K&N filter will be higher in real life scenario due to the increased surface area exposed to the air stream.

 

 

 

 

Though the K&N air filter was found to render slightly better performance compared to OEM style paper air filter, the very high cost of K&N air filter (Rs6500/-) compared to that of the OEM air filter(Rs200/-) is a deterrent. From the tests we also see that clogged filter degrades the performance of the vehicle noticeably. But from a practical point of view the effect in degradation of performance was found to be negligible.

[Rod21]

7 minutes ago, 69fastback said:

tons of info for you here, with some factual data  K&N has great marketing and poor filtration, with minimal performance benefits  

 

 

https://pdf.sciencedirectassets.com/282073/1-s2.0-S2212017316X00047/1-s2.0-S2212017316301475/main.pdf?X-Amz-Security-Token=IQoJb3JpZ2luX2VjEIj%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaCXVzLWVhc3QtMSJGMEQCIFc3Q%2F6xoWJEnJR0DZt6bdgIU7PrTimU5JIbctlDFptuAiBJAwgujH1nhOFaEX%2BTr6K8NqJh2pdOvdp9EXHgx5m87Sq0AwhREAMaDDA1OTAwMzU0Njg2NSIMefbrFPqGxdnqAvFkKpEDuCTgY76%2FVTcSFkYAYnoOV4JsqU1XM1DaNvAay6JLUuZ8Pt2d8OmOxvL7cZ9uKyd1MwRlNtqo2S5JNKc3fDG%2BulIU45dwHnHwnFIefx0lPL9w7in7YoECj6%2Fo5sOmhJZupwjiBJAH5O7aXm2tjIDtGxHk0vmA8RCtQFm%2B%2FH%2FURsi9a%2FbvXM3uXEtSNVi4UdqeShFb8WfurKI4WEMhlrKv8e5gCpJEYpdOFqUFmFcxt4M4ULDDGP%2FZgTamy8dHSFAC72%2BjPsyro2C3tBY4lo9jd5B5rVpGtJqnN1Wmk6P3l77JoH28iA8iyBRX3B4KjDfxFu55NPl0q0njNmeayVoZ%2FhxgB9%2FgRGrll%2FsXKdXpllA0ZuYFh15bw7fb5ESZy6kkD%2BB0QiQH3%2BHQcuoNCoJtIUFjMIdhflpPEGd%2BFaQ%2BGd%2F36%2Ffw0EKEM4Zq%2FPo9HOJdhT%2BMns9WvE9hC7w8%2FJGBC0aqqYBkPTFEbYHP%2FDlvLPnm%2F0RhDX7z6gMlA0vlgdo9NHA%2BUsN7vaS7B5%2F%2F1YFkDtcwn92S%2BQU67AF%2F4S7ROMRsyTqDPBQph48dta42VNEWZ9djt7%2BD%2FEt9u9ZjV1RA8AWqjh9q3ow0j0VthrQKhnBSTgw0nfEn3iqDHXsucgzPYg5pwrlKLYxi%2FwxVNJ%2Bt3%2Fa5nkVU4k9dYoPCzVczXJrdhMQtBTAApn%2FIohJ81hQHqP%2BFAWJ%2Fdy9Hdfs18qi9GGNU9%2Bj%2By%2BvvM%2FyuMye6wMjStkUenbNjaf%2FaNEmUwFLtGHbyVqw9e8WkAGFPlm6Q3iHK9Zn4%2BEgo%2BCUXI5%2FoqOEcbx%2FmUZ7S6ywcIEPSjYIdjeCpH8%2BULuLC8WUBA1c871%2FrW9wyDw%3D%3D&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20200801T010338Z&X-Amz-SignedHeaders=host&X-Amz-Expires=300&X-Amz-Credential=ASIAQ3PHCVTYX575NWMP%2F20200801%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Signature=739f49da11efe03c10eb8475dd33b1604df6c28bfdca6f9dbce914ba9f974180&hash=1a4a1cf5fee2987e093485f12d3ffb65053e497af2fae8bd0c575d58689a3636&host=68042c943591013ac2b2430a89b270f6af2c76d8dfd086a07176afe7c76c2c61&pii=S2212017316301475&tid=spdf-275bb632-bd1c-4d9b-af40-95681a52595a&sid=eaae5d9b469f7749995b87d47fc5746b1924gxrqa&type=client

 

 

 

 

Fig 8 shows that the filtering efficiency of the OEM filter was superior to that of the K&N filter. The decreased filtering efficiency of the K&N filter can be attributed to the increased pore size of the cotton gauze medium used in the filter. The actual filtering efficiency of the K&N filter will be higher in real life scenario due to the increased surface area exposed to the air stream.

 

 

 

 

Though the K&N air filter was found to render slightly better performance compared to OEM style paper air filter, the very high cost of K&N air filter (Rs6500/-) compared to that of the OEM air filter(Rs200/-) is a deterrent. From the tests we also see that clogged filter degrades the performance of the vehicle noticeably. But from a practical point of view the effect in degradation of performance was found to be negligible.

Seen the bad data on them but that doesn't scare me off. I think you'll be ok with regular servicing. If I raced perhaps reconsider, but for me ... a filter unit that is a basket works perfectly. 

 

[The Inquisitor]

13 minutes ago, liberty2701 said:

I ordered a Unifilter with oil.

Lets look at it this way,

What its folding the air filter tight to the air box?

My DRZ has a metal wire pressing the filter which I'm assuming is the same as you bike and IMO does not press as tightly an air filter that has a center bolt to can really press the filter into to seal like @Rod21 posted

I'd be slightly interested to here how the Unifilter foam fits/work and if its a tight seal on your bike if you feel like posting your results later.

Good Luck