K11 Owners Group

Geoff · Posted: Thu Mar 04, 2010 5:26 pm Post subject: K&N Air Filter: Worth The Money?

I'm considering a K&N air filter for my '94 K1100RS. K&N claims their filters offer performance gains, but I'm not sold. If anyone has tried a K&N, I'd appreciate hearing your thoughts.
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2000 R1100RT
2008 H-D Electra Glide Ultra Classic

Tim (Midland Section) · Posted: Thu Mar 04, 2010 5:46 pm Post subject:

IMNSHO K&N's for a K are a waste of time, money & effort. The standard filter flow matches the injection system, Is big enough to allow more than enough air through, even when partially clogged. Given that the standard filter is a PITA to change, is having to wash & re-oil every few thousand miles worth it??
Just my 2 Pence (cents).
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Grey haired riders don't get that way by pure luck
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1972 750 Commando
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RJTrucker · Posted: Thu Mar 04, 2010 5:52 pm Post subject: K&N vs Stock

I have used both. The K&N is nice but it needs to be treated with oil and gets dirty and clogs faster then the stock one. Since the air filter is not an easy part to get out and put back in I have been using the stock filter. If you use the K&N with out treating it it does not filter as well as the stock one. The K&N is reusable with a good cleaning and retreating and the cleaning kits are only $15. Over time I am sure the K&N will be a cost savings but I am not sure the K bikes will be arouond long enough to recoup the costs.

Ron
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Ron
1993 K11LT
1985 K100RS with over 100K on it
1985 K100RS Luftmiester Turbo Work in progress (any help is appreciated)
1974 R90/6

Geoff · Posted: Thu Mar 04, 2010 6:12 pm Post subject:

Thanks for the feedback. I didn't consider the K&N's cleaning interval and the difficulty accessing the air filter. If there are no performance gains, then I certainly don't want to deal with filter removal/installation any more than I have to. I think I'll stick with the stock air filter.
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2000 R1100RT
2008 H-D Electra Glide Ultra Classic

RAL88 · Posted: Thu Mar 04, 2010 6:15 pm Post subject:

What I found with the K&N that I had tried is that where it is placed on the bike it gets a lot hotter than what you would find under a car hood. This causes it to dry out even faster. I found that mine was dry between 300 and 500 miles of riding with it.
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Rich

"If it ain't broke, take it apart and make it work better"
*************
'96' K1100LT-SE
'97' R850GS-R

Flying Duck · Posted: Thu Mar 04, 2010 6:44 pm Post subject:

Also, take a look at the size of the air filter. It's pretty frickin' huge for a one liter engine if you think about it. K bike air flow is not holding your engine back.

+1 on K bike heat drying the oil out relatively quickly.

K bike guru Don Eilenberger did some dyno runs on a K75 to compare air filters. He found no change in power output if half of the OEM air filter was covered with celophane. No change in power with a K&N either. He also performed some other tests and discovered that the K&N let more crud through too. Whether or not that would eventually kill a bulletproof K engine I don't know but since the OEM ones cost less and do a better job, it's probably wisest to go that way.

The factory service interval of 12k is ridiculous. Change it every 50k whether it needs it or not. Or take the Phil Marvin route: Pull it out, blow it clean with compressed air and put it back in.

K&N is the Amsoil of filters. Lots of marketing hype.

There may be some racing applications where K&Ns make sense but they're a big waste of money on K bikes.

You do get a sticker though. Very Happy

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93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
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mnb · Posted: Fri Mar 05, 2010 1:24 am Post subject:

K&Ns filters (also their oil filters) are pourous and let more stuff through. This can potentially cause damage that would be prevented by a better filter.

Save your money on the air filter and spend a little more on the oil filter and avoid K&N.
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1997 BMW K1100LT ABS Special Edition
2003 Husqvarna TE610e
2007 Harley Davidson Road King
2009 BMW F800GS
2011 Husqvarna TE310
2014 Ducati Multistrada Pikes Peak MNB Edition

ChrisWeeK1100RS · Posted: Fri Mar 05, 2010 3:17 am Post subject:

The only time I ever used a K&N on one of my bikes I swore never again. Not only did water perpetually get into the carbs everytime it rained, so did a lot of gunk. In all fairness these were the open pod types bolted directly onto the carbs though, and the heat from the engine (and ambient temperature) dried them up pretty fast and it's a real hassle to re-oil them actually, plus it's a 'special' oil and costs a bomb here. No thanks.

Chris
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"Ride hard or stay home..."
'93 BMW K1100RS
Mileage: 37,000km-ish
Malaysia

duckbubbles · Posted: Sat Mar 06, 2010 11:40 am Post subject:

A few years ago someone did dyno testing that indicated the stock filter is about as good as it gets. They tested K&N with no improvement and no filter at all didn't improve the numbers. I ran a K&N for years but changed back after I saw that test. The K&N is much more flexible and is harder (in my experience) to get to fit correctly in the airbox and seal right.

Frank
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85 K100/1100RS, 321,000 miles, 25 years
96 Ducati 900SS/SP, sold it
05 R1200ST, 35,000 miles, 5 years
400,000 BMW miles

John Clauss · Posted: Tue Mar 09, 2010 8:42 am Post subject:

One of my friends is a BMW guru. He worked for Butler and Smith and is a font of BMW knowledge. Ask him about K&N filters and he will go on for hours about how awful they are. He will tell you about the ruined engines, carbs injectors and all sorts of stuff. DO NOT ever think about K&N filters, stick with the stock.
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1997 K1100LT
1975 R75/6

It will bring you so close to nausea, it will make you sick! - Big Al

BobZ(IL) · Posted: Tue Mar 09, 2010 5:06 pm Post subject:

I'm with you all on just using a stock air filter in the K bike.

But I gotta tell you, when I put K&N in my 300ZX Twin Turbo along with cat-back custom pipes, the turbochargers spool up twice as fast as before. That thing really breathes now.
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'93 K1100LT
'78 R100S
'05 R1200GS
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Live well, do good work, enjoy the ride.

drikko · Posted: Tue Mar 09, 2010 5:13 pm Post subject:

Sure, but for how long!! Make sure you save some money for a full engine/turbo rebuild Shocked

I had a K&N on my diesel Landcruiser, a mechanic friend of mine was horrified and made me take it off while he told me how much it cost to rebuild a 6 cylinder diesel Toyota engine.
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