K&N has the benefit of being rechargeable and only needs cleaning every 50,000km. So in theory I should never have to buy another filter for the life of the bike, and it was cheaper on fleabay then OEM, which was a bonus. I have run it for the past year and haven’t noticed any issues with A/F ratio.

 

wow i had no idea this was going to be a hot question to ask.
my bike is an F4i with just over 20Km on it.
i guess by better i did mean air flow, yes the stock will breath in as much as the engine needs. and since its the suction of the piston taking the air in, not the filter pushing the air, i am not sure the whole A/F ratio being effected all that much, plus that's why most bikes have sensors, they can adjust the injector timings to match the 2-5% extra air flow. not that is going to make a big difference anyway.

as for tuning, yes im still stock, going to cut my muffler soon but i don't think its going to do anything for power, maybe 1%.

jetting works on carbs, i don't have jets, the FI relies on timing and pattern, maybe a good cleaning of the injectors would be different. i don't think i need any 'tuning' since almost all my parts are still stock.

i guess i was more asking for personal experience rather then an argument on the type of filter.

i did get a few about K&N and i have personal experience with it in my car as well. but not on a bike.

and the trick to the filter isn't so much the extra dirt on the filter, its the bigger holes getting plugged. that's why they say not to wash it with heavy pressure water, you want to keep some of the dirt on, so just a light brushing and soap/water would do the job, of course followed by lots of oil to stick the dirt to.

 

For your bike k&n is a waste of money IMO and servicing it every oil change would only make it pass more dirt. K&N recommends inspecting every 25k miles and service typically at 50k miles from their FAQ. Here is a link to k&n's site w/ pics of how to tell when your filter would need cleaning Dirty and Clean Air Filter Pictures.

 

Most non paper filters flow more air than paper filters. There are other ways to filter particles besides the size of the holes in the filter. Paper filters are the only ones that depend on that method which is why they flow less air.

Most people don't understand that which is why K&N has critics on the 'net. K&N has sold millions of filters and give one of the if not thee best warranty in the business. If you believed everything you read on the internet the streets would be littered with blown engines due to K&N yet you never see a complaint by an actual K&N user. Which I am not one of , just for the record.

Anyway, any good brand name filter will do just fine. If you find one that will flow more air your fuel management system will recognize that and adjust the ratio (within reason) to accomodate. The gains made thru air filters changes though are extremely minimal and rarely every noticed. What fools most people is the intake sound very often increases which leads to the 'feeling' of more power. Gains shown on the dyno, and yes there can be, are not enough that your 'seat of the pants' could tell with out the sound.

So for what its worth, thats my opinion. As usual I'm sure YMMV.

 

If you have a perfectly working oem paper filter...why trash it and replace with after market? Until the oem one get old and needs replacing, go ahead....but if your bike is stock & FI? Don't know if it's the best...but for the older bikes like mine, carburetor and exhaust system..my bike love the K&N...intake sounds strong...love it. It's a pain to remove tank to get to filter for cleaning though. Usually I'll clean the K&N every 2-3 oil change....

 

I don't think anyone ever said it's gonna ruin the motor but it will cause more wear than the oem paper filter by allowing more dirt into the motor. Here is a link to a filter study from awhile back http://home.roadrunner.com/~jbplock/ISO5011/SPICER.htm, guess which has the lowest filtration efficiency. K&N's cotton gauze technology is old and outdated, pretty much every aftermarket automotive filter manufacturer that used to use cotton gauze has moved to something else. If you think that k&n users never complain about them go look on bobistheoilguy, there are plenty of people who used them and their used oil analysis showed more dirt in their oil w/ the k&n. On the flip side there are others who had no such issues, it depends on the application and environment. If there were good filters like the aem dryflow or afe dry filters for cars available for our bikes that would be worth looking at b/c they filter well and are cleanable/reusable.

 

K&n makes two filters. One with cotton gauze for racing(less filtration for better air flow) and then one for street. If you follow my link there are the filtration tests for the steet filter.

 

Nonsense but believe as you like.

 

What are you referring to, the study was performed independently. Cotton gauze is pretty much the worst air filter media that is still in use. Trust me I've done the research and can link to more test results, although in your opinion lab tests conducted to the same standard automotive manufacturers use are nonsense.

 

my bad dirt, i remember you talking about it, i only remembered one of your f3's giving you hell for it LOL.

the old zx6e i put back together refused to cooperate with the k&n filter it came with. stock did the trick and it was fine ever since.

my f3 loved the k&n as well, presuming i cleaned it and recharged it exactly as the instructions asked.

my 900rr refuses to run correctly with an airbox (forget the filter!) now that it has FCR41 flatslides on it. Way too much fuel going down the intake for a box on top! I have to use pods, and the pods i use are k&n (really just availability on that one) and they run well for their purpose. I pull em off for the dragstrip because it runs 12.5 a/f wide open with the pods on, and 13.5 with them off. so even the k&n's are restrictive in some ways.