K&N Air Filter

[Andy Clap]

Thinking of fitting a K&N air filter as posts here and elsewhere say it improves midrange
1. Is this right?
2. Is it a direct swap, without the need to re-jet or mess with the carbs?
3. Are the filters washable like some of the car ones?


Ta 

[darrsi]

Just do it and enjoy, you'll have plenty of time to research it.

[papercutout]

If you'd not guessed, this gets asked a lot.

You shouldn't need rejetting, unless something is already wrong or you're making drastic exhaust changes as well. It should just need the occasionally re-oil (from memory). I didn't notice a mid range difference, but at the same time, I'll never need to change it again.

[Andy Clap]

Ta 

[Fazer Forever]

I've just fit a K & N air filter to my bike after 12 years of ownership and it feels more eager to rev than ever before.
Definitely a big improvement and no other mods done.

[dcurzon]

Service schedule is 50k miles.  I think you'll be alright

[paulchucky]

fitted one in mine early this year
already had an open can
it seems to help it breathe better and gives its a nice snarl at 10,000 and lets the top end rev out
all in all a worthwhile improvement
oh n it aint gunna nedd a wash for a couple years 

[Arbie]

Fitted one too. Straight swap.....runs sweet with my race can. Happy days.

[Adrian6171]

Fitted one in April this year,can,t notice a difference in power but the growl from about 5k upwards is noise you just love to hear when on the bike.

[Andy Clap]

One added bonus, apparently it reduces your gas consumption 


Maybe I won't bother insulating my loft now.  God Bless you American filter makers.

[tweetytek]

If it lets more air in then surely the air/fuel mix ratio will be out and so I'm not getting why foccers above feel that no further mod is needed; unless of course the bike runs slightly rich in the first place - but mine doesnt - and the plug electrodes are a white tan colour which indicated to me that I  would not want to go any further with in terms of letting more air in as I suspect the plugs would overheat.

[darrsi]

If it lets more air in then surely the air/fuel mix ratio will be out and so I'm not getting why foccers above feel that no further mod is needed; unless of course the bike runs slightly rich in the first place - but mine doesnt - and the plug electrodes are a white tan colour which indicated to me that I  would not want to go any further with in terms of letting more air in as I suspect the plugs would overheat.

We can't all be wrong?

[tweetytek]

If it lets more air in then surely the air/fuel mix ratio will be out and so I'm not getting why foccers above feel that no further mod is needed; unless of course the bike runs slightly rich in the first place - but mine doesnt - and the plug electrodes are a white tan colour which indicated to me that I  would not want to go any further with in terms of letting more air in as I suspect the plugs would overheat.

We can't all be wrong?

I'm not disputing that, but rather trying to understand the logic here, which tells you that if you put more air in then the bike runs leaner; which is not what all of you are saying, which is why I dont understand. ?? unless the bike is running slightly rich to start with - as some indeed do

[Adrian6171]

From what most of the guys have been saying on the forum is that the bike is set from the factory to be running a little on the rich side thus no re-jetting required.

[tweetytek]

yep  ,  which is why I said above ...

..unless of course the bike runs slightly rich in the first place - but mine doesnt - and the plug electrodes are a white tan colour which indicated to me that I  would not want to go any further with in terms of letting more air in as I suspect the plugs would overheat.

[paulchucky]

yep  ,  which is why I said above ...

..unless of course the bike runs slightly rich in the first place - but mine doesnt - and the plug electrodes are a white tan colour which indicated to me that I  would not want to go any further with in terms of letting more air in as I suspect the plugs would overheat.

understand you there tweety if your at a nice tan colour thats all good  if your running white you either weak or got an air leak !!


sounds like you need to richen her up abit  even if you dont fit a k+n  it still better to run slightly rich rather than weak as weak will make it overheat and  possibly if not probably cause problems
warm engine up n go out for a ride n do a PLUG CHOP
get a quiet stretch of road run the bike up to say about 4th gear 7000-8000rpm n hit the kill switch  pull over n take no1 + no4 plug out and examine
adjust as necessary etc 

[tweetytek]

I'm going to ride out in the next few days then adjust the pilot screw's with the help of a gunsons colortune then sync the carbs. Might do a vid

[paulchucky]

dont use a colourtune


plug chop it`s a better result as the enginges  working under load and in natural  enviroments  etc




colour tunes only work as the bike is idle   ie not moving so only in stale surrounding n still run weak !!!!!! not good


ive set many engines even on rollling roads   and still  refered back to plug chop !

[tweetytek]

dont use a colourtune


plug chop it`s a better result as the enginges  working under load and in natural  enviroments  etc




colour tunes only work as the bike is idle   ie not moving so only in stale surrounding n still run weak !!!!!! not good


ive set many engines even on rollling roads   and still  refered back to plug chop !

I've used colortunes for 34+ years and it works

you mention that the bike is idle and a "stale" surrounding; you set many on a rolling road - what , set the pilot screw mixture on a rolling road? WTF?  I must be a dumbass as I dont know why one would  set an idling circuit on a rolling road  etc.etc. Come on mate, you kno this but...ahem, the pilot screw only adjusts the mixture for idle principally, so idle and not moving is what is required for pilot screw adjustment - albeit the bike needs to be warmed up. The colortune provides a visual cue to the mixture which whilst not perfect is far better than the audio "listen to the RPM" and more accurate. Its not perfect, but a better solution. I have to say I find your comments most illogical but hey, you are entitled to your view and if your approach has worked then disregard my shite and carry on turning the pilot screw while the bike is motoring along on  a rolling  road   

[paulchucky]

im not saying that setting up whilst stood still isnt the way
what im saying and im sure you`ll agree is that the bike spends most of it`s time out on the road and that the engine is therefore under load  most of the time, which is where "IF any" damage will occour.


once off tick over at approx 1/4 throttle the mixture is controlled by the needle  untill it reaches approx 3/4 throttle where it is then controlled by main jet and the air volume available ie: air filter restrictions   so yes although basic  mixture is set at tick over  etc  moderate and 3/4 throttle is where the engine spends most of its cycle
 unless your a power ranger n just pose at the local cafe


now without using dyno`s n rolling road set-ups which i doubt most owners don`t have in there shed
 i`m purely giving an easy way that most owners can do very easily with a screwdriver and a plug spanner and does`nt cost anything and help the owner learn abit about there ride .

[rodrigojds]

I bought a K&N air filter last week and I've noticed a few things.

The very first thing I noticed was that the idle RPM's are lower now than before. Previously I would start it up and the RPM's would go to around 1.25 K and now I start it up and it goes to less than 1K. But after a while it goes to 1.25 K so I'm guessing it's not an issue.

Another (very) positive thing is that the RPM's easily go to + 12K and before it would rarely pass 8K.
Also the sound the bike makes when I accelerate is louder!


Even though it was expensive I'm happy that I bought it. 

[darrsi]

I bought a K&N air filter last week and I've noticed a few things.

The very first thing I noticed was that the idle RPM's are lower now than before. Previously I would start it up and the RPM's would go to around 1.25 K and now I start it up and it goes to less than 1K. But after a while it goes to 1.25 K so I'm guessing it's not an issue.

Another (very) positive thing is that the RPM's easily go to + 12K and before it would rarely pass 8K.
Also the sound the bike makes when I accelerate is louder!


Even though it was expensive I'm happy that I bought it.

It'll be the last one you buy for the bike so it wasn't really expensive!
And it's worth it just for the general better feeling of the bike anyway.

[clayt74]

With standard air filter mine ticks over between 1.6-1.8k which I thought was the norm? Rev wise easily over 12k all the time!! Still wanna fit a k&n tho

[BBROWN1664]

The FZS runs slightly rich from the factory. No need to change the carb jets when adding either a K&N or a different end can. Just reset the TPS and balance the carbs properly to fully enjoy the (slight) increase in performance. The most apparent difference I found was in the mid-range where it just smoothed everything out nicely.

[clayt74]

I've got a set of carb  gauges but haven't used them yet, is setting the tps just using the rpm  meter to show  it's in range?