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OEM or Hi Flow Air Filter

1159 Views 26 Replies 10 Participants Last post by  David37

Any advantage to going with a high flow filter in the stock air box? When searching most results were on the subject of pods which I have no intention of doing. I don’t put enough miles on the bike to care about re-usability and cleaning it, just if there is a performance angle.

Next up- is there a good online retailer or forum sponsor for buying OEM oil filters and fluids? I’m never near my dealer so I’d rather just order it from somewhere.
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You can’t get a filter that flows significantly better than OEM paper without sacrificing filtration. Considering this is not a high performance engine, I can’t see why you would want to make that trade but it’s up to you.

As for the cost of reusable filters it’s hard to see that ever working out in your favour unless you regularly ride in very dusty conditions.
I think you may be missing the point I made about the R9T catching crap in the filter way sooner than other BMW boxers due to the inlet not being behind bodywork etc but pretty much out in the breeze, it cakes up at about 10,000klm. As to sacrificing filtration by using a K+N , every time I remove one for a clean/re-oil I run a clean soft tissue paper around the air box to see if any fine dust got through the filter, the tissues come out pristine. I don't know if you do your own maintenance , if so you'll find the filter surprisingly dirty. A lot of owners here tend not to keep a bike for any great length of time so in that case the K +N likely seems a little pointless, but if keeping a bike or car for the long haul they do start to make sense. I just looked through some old maint. logs I keep, I've been using K+N filters for 41 years!:cool:
I do my own maintenance but my Classic is an on road machine and I haven’t noticed any great buildup of dust. Hardly surprising given its usage but other people will have different experiences and your point about the air intake design certainly makes sense.

I have done plenty of reading about filters in the past and oiled filters never came out on top in independent testing for filtration. It could have changed in the last few years but I haven’t heard of any real improvements in the technology. I’m also not saying it filters poorly but I personally don’t see the point unless you really are having to clean it a lot. I mean I can buy roughly 4 filters for the price of a K&N, plus oil and cleaning products. It’s less work/mess and it filters better, so that’s where I spend my money.
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The OEM paper or similar is cheap and highly effective.

Word of warning if you are doing the change yourself. If the front fitting on your intake snorkel is particularly tight be very careful when trying to work it loose. I snapped my intake and had to order a new one. I suggest putting some sort of strap around the front of the snorkel and the frame just lose enough that you can pull the fitting out but that will stop it bending out too far when the fitting suddenly comes loose.
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do you have to do a tune flash after changing to K&N filter ?
You will not need a tune for tiny changes in air filter flow rate.
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