K&N Air filter

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felix barrao
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Joined: Sat Sep 08, 2018 4:20 pm
Location: Zaragoza ( Spain)

K&N Air filter

Post by felix barrao »

Is it recomended?

I have read some negative feedbacks in stock bikes.
Thanks
tony.mon
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Re: K&N Air filter

Post by tony.mon »

Yes, if you also get the carbs set up on a dyno.

There's no point unless you have free-flowing cans or a full system, and perhaps airbox work.

If you fit them to an otherwise stock bike it just messes up the fuelling.
It's not falling off, it's an upgrade opportunity.
felix barrao
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Re: K&N Air filter

Post by felix barrao »

Thanks.
I bought my bike second hand, and actually I don´t know if it has any carb modification. ( It has leo vince exhaust installed)
The engine works like a charm, very fast response in any situation, very very happy with it, fuel consumption is within limits, ( between 7,7 and 8,3 l/ 100km ) nothing to complain. But, yesterday I dissembled the db killers, and notice a matt black cover on them, sowing that the engine is working in the rich side. I assume that the K&N filter will lean a little the mixture, and maybe this will help.
I found the K&N at a fair price, ( 82,90€ shipped to my house) and I was considering it.
jchesshyre
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Location: Chester, Cheshire

Re: K&N Air filter

Post by jchesshyre »

Some interesting thoughts on K&N and other oiled gauze filters here:

https://webcache.googleusercontent.com/ ... clnk&gl=uk

(I've linked the cached version as the site is currently offline).
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Stephan
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Re: K&N Air filter

Post by Stephan »

KN filter can give you few more hp, but if you need to solve engine running rich there are better ways. Oem paper filter is good to go in terms of filtration efficiency and maintenance.

I would rather pay one dyno run with afr measued. After that you can play with pilot jet setting or sizes, needle position, main jet sizes. Jets are relatively cheap to buy.
Or you can end up just with slight pilot screw adjustment or do nothing, if you say bike is running fine.
felix barrao
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Re: K&N Air filter

Post by felix barrao »

Thanks for the link, very informative.

Stephan, he engine works impressive at the moment, ( can´t be more happy with it) but, I have the opportunity now of buying the K&N at a good price, so the question.
Also since the engine works in the rich side thought that, maybe a less restrictive air filter can help, but generally speaking I haven´t heard good comments about K&N filter on this bike.
jchesshyre
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Re: K&N Air filter

Post by jchesshyre »

The other thing to note (as has been discussed on here and on the US site in the past) is that with these bikes, changing the airflow can have unexpected results on the mixture. Because of the size of the carbs and the fact that they're almost too big to work well, improving the airflow can paradoxically richen the mixture. The ideal airflow through the carbs is 'laminar' rather than 'turbulent', and in stock form the airflow is partly turbulent, which leads to the particular size of main jets, needles etc. that Honda settled on (actually they didn't totally settle on them, with slight tweaks over the years the bike was produced). Improving the airflow can lower the extent to which it is turbulent, leading to more fuel flowing through the jets at a given jet size. People doing serious tuning on these bikes have had to use significantly smaller main jets than stock as a result.

I am not an expert, rather I've just done a bit of experimenting and a lot of reading, but have a search on here and superhawkforum.com. Look particularly at posts by 8541Hawk, whose carb setup experience with these bikes is a sticky on both sites.

This is just a heads-up that installing a K&N filter, as well has having the possible implications of letting more dust into the engine as discussed in the link I posted above, may not *necessarily* give you a leaner mixture - it may even cause it to richen.
Last edited by jchesshyre on Mon Jan 14, 2019 8:15 pm, edited 2 times in total.
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Stephan
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Re: K&N Air filter

Post by Stephan »

felix barrao wrote: Mon Jan 14, 2019 5:38 pm Thanks for the link, very informative.

Stephan, he engine works impressive at the moment, ( can´t be more happy with it) but, I have the opportunity now of buying the K&N at a good price, so the question.
Also since the engine works in the rich side thought that, maybe a less restrictive air filter can help, but generally speaking I haven´t heard good comments about K&N filter on this bike.
Maybe it is running rich, as judgement from exhaust baffle being black doesn't seem to me very accurrate.
If it is running rich, you don't know where exactly. It can be only low rpm range (adjusting pilots), or middle. And you don't know effect of kn filter through rev range as well.

For me it is not question of good deal on filter. Altough I cannot say kn filter itself is bad idea :) More power is here definitely, but with proper setup.
Last edited by Stephan on Mon Jan 14, 2019 8:42 pm, edited 1 time in total.
felix barrao
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Re: K&N Air filter

Post by felix barrao »

Thanks for the info.
I will stay in the paper filter then, the engine works awesome, ( and it´s a 97 model with 90.000 km on the clock). The power is more than enough for my usage and the fuel consumption is ok, ( between 28 and 30 mpg)
jchesshyre
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Re: K&N Air filter

Post by jchesshyre »

The other thing to say is that these bikes seem to like to be a bit on the rich side. Unless you're getting misfires and/or a reek of unburnt fuel in the exhaust, I wouldn't worry. Certainly some soot in the exhaust pipe isn't enough alone to diagnose rich running.
felix barrao
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Joined: Sat Sep 08, 2018 4:20 pm
Location: Zaragoza ( Spain)

Re: K&N Air filter

Post by felix barrao »

:thumbup:
Thanks
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fabiostar
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Re: K&N Air filter

Post by fabiostar »

id leave well alone sir, Honda done a fine job of making huge carbs work and its hard to get better, i played with mine and the more air i got into it, the richer it ran??? figure that one lol
the older i get,the faster i was :lol:
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