K&Ns are the cat's meow when there isn't fine sand or very fine dirt in the air. In the right environment a K&N will pass more air when dirty than a clean paper filter will.

If you live where there is fine sand and/or very fine dust and dirt the OEM paper filter with the OEM foam pre-filter is a better choice. In some instances a totally foam filter is OEM (a la the old Filtron foam motorcycle filters) and properly serviced is the best at stopping fine dirt and sand.

Personally I would use one if there was a oiled foam prefilter wrapped around (or on top of) the K&N to stop the fines. Don't care too much about the enhanced air flow (it's a lawn mower after all, LOL) but not having to buy new air filters would be a big plus. Of course their recommended cleaning kit is kinda pricey so that has to be factored in. Using gasoline to clean the filter damages the rubber gasket/seal, as I have found out.

K&Ns really hate pre-filters and they are not recommended.

Cutting off the air flow will effect the jetting. Less air and you run rich... even a lawn mower. Since very few people have their L&G rides correctly jetted (everybody doesn't live at sea level) they are running rich already. Starving the airflow usually will gas foul plugs.

Using gas to clean a K&N also degrades the folded element.

My wife SUV air filter 22 bucks. K&N is 60 bucks. We plan on keeping the car for 5 to 10 years. with just the savings on air filters I can probably by new lawn tractor LOL. My conditions are not favorable for K & N on my lawn equipment. on lawn equipment I don't see why you can use the pre-filter with the K & N?

I've not had experience w/ K & N. A look back in the book shows them as "high flow' and no mention of a prefilter. Hmmmm. Some online reading shows a wrap available tho. With all the filter related failures, one would think a priority would be to keep the dirt out. . . Me thinks if they want them to fly, some better marketing is in order for OPE.

rc,

Did you mean to say "you don't see why you can't use a pre-filter with the K&N?

K&Ns are deigned to flow at least the same volume of air as the OEM element so on EPA regulated engines that have to run correctly from sea level to 10k feet (but rarely do) the design parameters of the air intake and tuning of the carb aren't affected.

Put even a dry pre-filter on a K&N and the volume of air it can pass drops dramatically.

In another life on AMA flat tracks we used to put a woman's nylon stocking over naked K&Ns to keep the mud off and sometimes had to rejet to compensate for the nylon stocking. You wouldn't believe the nylon would cut down airflow but it does. An oiled pre-filter really chokes airflow down.

Then there's the debate over oiling pre-filters and not oiling. Many engine and L&G manufacturers specify oiling the pre-filter yet JD specifically says no oiling the pre-filter on their L&G products.

I'm no engineer, I don't play one on TV, and I didn't stay at a Holiday Inn last night so I follow the OEM recommendations and so far that hasn't failed me.

Have used K/N Filters on everything from Diesel Trucks , Automobiles , Dirt Bikes , Harleys and even Snowmobiles (ice crystals) Racing . They are Best form of Filtration I have ever used . Don't believe any form of Prefilter is warranted or would enhance flow characteristics . Follow proper oiling treatment and cleaning procedure's and they will last a life time loll .

I have been using K&Ns since their prototype days in the late sixties and have a lot of respect for them. I've run dyno tests on different air filters and K&N never ceased to impress BUT over the years I have rebuilt quite a few engines that had K&Ns in really dusty and fine grit environment so I won't use them in that situation.

Our experiences will vary dramatically based on the installation and the environment... I'm simply relaying my first hand experience over 40 years in a wide variety of environments and applications.

It is interesting to note that back in the beginning K&Ns were marginally more expensive than OEM filters and now, well now you have to save up to buy a K&N.

They're better than nothing, but not by much.

OK Guys, I am willing to confess to some ignorance, and since there are (probably) others unwilling to do so I am going to ask rather than look it up!. What the heck does "K" and "N" stand for?

I'll also make one point. "High volume" is a stupid designation. The volume of air will not vary substantially since it is the volume of the cylinder (yes, with enough negative pressure there will be slightly less air). "Low resistance" or "easy flow" would make a lot more sense. Leave it to marketing....

I really don't know what K&N means but they built their reputation cause a K&N will flow more air when dirty than other filters will when they're clean and that's where (I believe) the high volume tag line came from. In the right circumstances that statement is true... I've seen it on a flow bench with my own eyes.

From Wikipedia: K&N Engineering was founded by Ken Johnson and Norm McDonald in 1969[1]. The name K&N came from the first letters in the founders' first names. K&N manufactures the majority of its products in-house. The company's largest overseas markets are Germany and Australia, and it generates approximately 15% of its revenue overseas.

I have one in two of my cars, but I have read in a truck forum that there is a service notice/bulletin from one of the Big 3 US truck makers that a K&N should not be used in a turbocharged diesel due to early failure of, I think it was the turbocharger. Too many fines getting by in the normal dusty environment of a work truck. Like I said, I would still use one in a lawnmower if it had a pre-filter, but that's the only way.

I still like the oem filters myself, but I know that people can be K & N freaks. I see they have the common 4101 Briggs Quantum style filter. That brings up a point that for the guy that tips the mower incorrectly and saturates the filter with oil- would the regular K&N cleaner make it spankin' new again? I know I don't bother cleaning a washable paper filter at all, much less if it had been contaminated w/ oil.

Did you mean to say "you don't see why you can't use a pre-filter with the K&N?

Yes, some times my brain get ahead of my finger or is it the other way around???????????

Do you really think a pre-filter on LT using K&Ns would choke off enough air to create fuel mixture problems?? I could see it on Race car or anything high preformance that runs at high RPM that sucks huge volume of air.

I was thinking about putting K&N in the wifes new SUV, but now I'm on the fence with all the negitive comments about not be able to filter fine dust? I live in a dusty area, but not like desert.

On my old walk behind Ariens tiller, I would keep using it until it became difficult to start and ran rich from a dirt/fines loaded up paper filter. Then I would put a new one in and off I'd go, like most people do I think. In reality, the air-fuel mixture constantly changes from leaner to richer as the filter gradually loads up. You're only kidding yourself if you think it runs at the optimum mixture most of the time, until its time of replacement or cleaning.

I'm with you RC on second thoughts about putting a K&N in my wife's 2008 SUV. It's not a sports car in need of every Cubic Foot per Minute of air flow, and I don't want to take any chances on ingesting fines into the cylinders of that expensive vehicle, so I will use the factory recommended air filters. But as I mentioned, my two older cars each with over 100K miles on them have K&N's with no apparent problems or oil consumption and in that case I'll take the chance and keep using them. I've used K&Ns in other cars and on my Norton motorcycle, also with no apparent problems.

When I say fine dust and sand I'm talking ATVs in the boonies and a GT mowing in it's own storm for a couple hours.

Any contemporary car/SUV/truck has a complicated enough still air box and baffles to eliminate that potential problem... well, unless it's a Border Patrol SUV.

"Do you really think a pre-filter on LT using K&Ns would choke off enough air to create fuel mixture problems"

Pull the AF out of your GT and slide the palm of your hand over the carb throat. I'm sure you'll be surprised how much your tractor sucks.

Well, how about going up one main jet or two, that'll sure screw up the mixture and that will only be increasing the orifice a thousandth or two. But it's not the mixture that will be affected as much as the volume of air and the air speed so the fuel won't atomize as intended and then there's all sorts of weird stuff that goes on.

I've has people who tuned up their whatever and now it runs like crap. I go right for the air and/or pre filter and sure enough they over oiled it. They even over oil K&Ns cause when oil is good then more is better... right? When they do it on cars they can really drive the MAF sensor crazy and then it throws a code and the check engine light goes on.

larso,

It'd take a lot of dirt to screw up a couple Amals...

justa, tossed those a long time ago. Now I have dual 34mm Mikunis ;) Dead reliable, along with the Boyer electronic ignition. It's a two-kick starter every time now. I have no problem with upgrading a classic using newer, better parts...

" I have no problem with upgrading a classic using newer, better parts"

Upgrade might not be the best word... but that's another discussion entirely.

Never had a Norton on my lift that wasn't a one kick starter with Amals and points... single or twins including 750 Combats.

To mention the hallowed name of Norton adds class to the forum.

Hey, thanks for the kind words on the Norton marque JL. In their day they were one of the fastest bikes out there, a lot of racing heritage. I can still purchase any part on the bike I need direct from England. Owning an older British bike or sports car is an acquired taste to be sure, lots of fettling to do. I have owned this '74 Commando since it was new. Hard to let go of so I'll probably just keep it. There's a strong Norton Owners Club in the USA as well. Besides the Mikunis, I've also installed 10:1 Venolia pistons and a mid-range cam. Really helps bump up the power at our 5,000-ft elevation in CO. Sorry, didn't mean to hijack this thread.

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Good choice in year and right side shift... the way it should be.

With respect Nortons were never "one of the fastest bikes out there" but as the British say "up to a ton" and "TT" (tavern to tavern) they were formidable and a lot of racing heritage for sure. I've owned the Manx, the Atlas and Commandos and worked on them for many years.

We shouldn't hijack the thread but if you wanna talk fast... let's talk fast...

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Sweet Italian bikes there. I almost bought a Ducati 750GT instead of the Norton. A guy i work with has several Ducatis. And BTW, when I say one of the fastest, I'm talking acceleration. The 750 Combat was hard to beat back in '72.

Fastest and quickest are two different things.

There were bikes in 72 running quarter miles a couple seconds faster than any Norton ever dreamed of and had been doing it for three years.

The memories of the past are always grander than the realities.

Let's put this thread to bed...

"Sorry, didn't mean to hijack this thread." Hey larso, I think thread ended pretty sweet with the pics you and lurker posted. Always had a sweet spot for a snortin' nortin. . . It was good to get some views on the K&Ns on OPE while we were at it!

Don't forget Donnie Vescoes R5 Giant Killer's or Kawasaki's Venerable H1 and H2 2-Strokes or later Z-1 lol . But yeah the British Parallel Twin Commando was a sweet ride . I briefly owned a 69 750-S but finally found a real sweet 1972 Roadster Commando 60 + HP at 400 lb curb weight was attention getting from those 30 mm Twin Amals . Finally let her go in early 80's for some American made Milwaukee V-Twins . Great Thread Guys thanks for the Memories lol . :)

V Twin, you said... if the Ducati 900 SS Desmo above wasn't enough then... one of the early Moto-Guzzi V-7 Sports circa 1972

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A Buddy of mine had a Eldorado "King Kong" Tourer 850 back when I had my FLH Classic back in 1980 . We toured all the way from Michigan to Texas . Lots of Pool (Billiards) for Gas Money along the way lol . Actually to stay on track , that way probably the second last set of K/N Filters that I bought for a Bike lol :)

I used a K&N filter in one of my large trucks , cleanining and oiling the thing . I guess it was doing its job ,sold the vehicle to a dealer who removed it for fear of most people are not educated to take care of the filter or dont want to . He replaced it with OEM.I never bought another one I figure oem was doing the job.

ewalk, evidently you didn't stop in Oregon Mo for pocket billiards our you would of been out of gas money! LOL

I'll have to keep an eye out for you and your pearl handled cue RC next time through Oregon lol :)

K&N filters, (and other "performance" filters as well), will provide no benefit on applications such as this. They're marketed as "less restrictive" and they are "less restrictive", but it's to a point that the *less restrictive-ness* doesn't matter.

I can put a 2" spray nozzle on my 5/8" garden hose and it will be "less restrictive" than the nozzle it has now. I can wire up my house outlets with welding cable instead of the "restrictive" wire they have now. But at what point does it not matter? ;-)

Parts stores that sell them often have the ridiculous ping-pong ball demo set up on the counter. You can put an OEM filter element over the inlet to a small fan and turn the machine on and see how high the ping-pong ball floats in a clear plastic tube. THEN, you can put a K&N element over the fan inlet and try the "test" again. The ball floats higher in the clear tube, (which convinces many folks that haven't really thought about the whole thing), that their current OEM filter is costing them hp and mileage.

It's funny really. OEMs spend lots of $$ designing and building machinery, and then screw up when it comes to doing the math and figuring out how much air flow is appropriate for the application? Proponents often point out that some vehicle manufacturers have used "performance" filters in some factory applications...and they have. But if filters *in general* were "too restrictive", why aren't the performance filters used across-the-board? Small engines aside, take a look at the dyno snippets that are included in these products' ads. The hp gains that are promoted occur at higher rpms than where the vehicle in question will spend any of its time. Money savings over the vehicle's lifetime? Perhaps....if you don't count your parts and labor for washing and "recharging" with oil at certain intervals, or, you don't consider these filters' proven lack of effectiveness in fine dust conditions.

This is amusing as well:

"Since very few people have their L&G rides correctly jetted (everybody doesn't live at sea level) they are running rich already. Starving the airflow usually will gas foul plugs. "

If your mower is running fine and you're not fouling plugs and your eyes aren't watering while you're out mowing, then your jetting is just fine. I think you'll find that nowadays, small engines in general run lean if anything. You used to be able to set the choke and then turn the choke off as soon as the engine started. Now, you have to feather it for a minute or two. Take the "lean already" engine we're talking about and start it up cold without the air filter on and see if it's worse. It will be.

Your mower doesn't need more airflow, nor is your OEM filter "too restrictive".

It's marketing.

I've got your "even less restrictive filter" here for only $19.95.

It consists of some window screen and a large hose clamp. Also included is a bottle of honey that you must wipe all over the screen (uh I mean "filter"). You have to wash and re-honey it once a week.

It only blocks "coarse" particles, but that doesn't matter because your engine will "breath" so much better. It will also prevent pesky phlegm buildup in the intake manifold, which every mechanic knows is the single biggest reason for cars to run poorly.

;)

Funny stuff WOC! Ya think you could carve one out of honey comb and be just as good? I've never been asked for or ever seen a K & N on ope. I remember it coming up in the forum before though. If someone could improve on filtration elements for OPE, that would be one thing. Things are getting better with making the shrouds easier to come off / open up on some of the newer engines anyways to maintain better cooling. The Briggs washable filters seem to be a good concept, though if I mention it to a customer- all I get is a blank stare if I suggest they wash them. Of course, then there is the guy that washes or blows out at 150PSI his standard paper filter...