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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: mrkay on September 09, 2012, 06:38:48 PM

Title: throttle body air filters
Post by: mrkay on September 09, 2012, 06:38:48 PM
Hello,

I just purchased a 1992 K75 a it is going to be a project of mine for a bit (it needs work but runs well).  I noticed that each of the 3 cylinders have there own independent throttle body which is cool.  I was wondering if anyone knows if I could take off the normal air intake and put a single air filter on each of the 3 throttle bodies.  I thought this may look interesting.  Anyone know if this has been done before and if it would not make anything work incorrectly? If it is possible then what air filters should I use? Any ideas would be appreciated.
Title: Re: throttle body air filters
Post by: Inge K. on September 09, 2012, 06:59:31 PM
Welcome mrkay!

Inside the air filter housing you`ll find a air flow meter, your idea need some rethinking.

Inge K.
Title: Re: throttle body air filters
Post by: mrkay on September 09, 2012, 07:35:57 PM
oooo interesting im assuming that if that meter was taken out the bike would not run correctly then?  would it just reduce the life of the bike and still run normal or would that just mess everything up?
Title: Re: throttle body air filters
Post by: Inge K. on September 09, 2012, 07:54:02 PM
The bike won`t function w/o the AFM, it`s needed for calculating the fuel mix.

Inge K.
Title: Re: throttle body air filters
Post by: mrkay on September 09, 2012, 10:52:08 PM
Lol guess doing that mod is out of the question. 
Title: Re: throttle body air filters
Post by: Motorandy123 on September 10, 2012, 07:52:09 AM
You can do this;

(http://i1061.photobucket.com/albums/t478/MotoRandy123/K75/knfilt.jpg)

Title: Re: throttle body air filters
Post by: mrkay on September 10, 2012, 11:39:50 AM
You can do this;

(http://i1061.photobucket.com/albums/t478/MotoRandy123/K75/knfilt.jpg)



Nice.  Looks like this is on the right hand side of the bike right?  What size of filter did you have to use? Any special mods that needed to be done?  I'm starting to make my 1992 K75 into a cafe style bike.  I've seen some amazing cake K's!

(http://i145.photobucket.com/albums/r218/bigtoysinc69/CF37C31B-3D65-4CEB-BA1B-7ACE018FC0E9-4607-000004312D409798.jpg)
(http://i145.photobucket.com/albums/r218/bigtoysinc69/24CD1F12-F078-4E92-AB23-7EAFEB36D891-4607-0000043127E59509.jpg)
(http://i145.photobucket.com/albums/r218/bigtoysinc69/D74A5808-3A16-4534-9CCD-75A4A239AAE8-4607-0000043122BF71D3.jpg)
(http://i145.photobucket.com/albums/r218/bigtoysinc69/21708FA7-FF34-4586-8923-CE623856945F-4607-000004311E26A3A5.jpg)
(http://i145.photobucket.com/albums/r218/bigtoysinc69/137B8172-7E74-40BC-B882-35888279524B-4607-0000043116A4299F.jpg)


Title: Re: throttle body air filters
Post by: argent brick on September 10, 2012, 03:38:14 PM
Search this website and you will find a section about Larry's Special K bikes. Well worth the browse. Maybe find some ideas.
Title: Re: throttle body air filters
Post by: wmax351 on September 10, 2012, 04:16:41 PM
If you switch the fuel injection system to alpha-n, with a megasquirt/motec/etc you could do away with the AFM, or do a carb (why?).  But short of that, it has to stay there.

In regard to filters, there is no reason to get rid of the K75's air filter. It flows far more than the engine could possibly use. It is also a very clean location. You could remove the snorkel if you wanted a cleaner look.
Title: Re: throttle body air filters
Post by: Motorandy123 on September 10, 2012, 07:33:49 PM
There was a Luftmeister kit to do this;

(http://i1061.photobucket.com/albums/t478/MotoRandy123/K75/knfilt.jpg)

But you can do it your self. Just get a K+N filter, the one on their kit was;

From K+N WEB site;

RU-2450      1.75" Flange Dia.(44mm) - 2.75" Length (70mm)
                  4"x3" Base Oval Dia.(102x76mm)  top 3.5"x 2.5" (89x64mm)
                  0.625" Flange Length (16mm)
        Flange offset 0.5" (13mm)
        Flange angle 0 degrees

The flange can be made from a turbo blow off flange from Ebay. The kit plate measures;

The bolt hole centers on the plate are 71x30mm.
The plate is 93x52mm with a 15 mm high flange,
OD of the flange is 47mm. 


 
Title: Re: throttle body air filters
Post by: mrkay on September 12, 2012, 06:08:56 PM
Yea I wasn't looking for any performance enhancement just for looks.  Thanx for the detailed specs!  Shouldn't be to hard to rig that up.  I looked through the special K section and there are some great bikes.  When I get some extra cash I will be chopping down the backside of the bike so I can get a smaller custom seat o and get a lower rear shock so I can flat foot it instead of using my toes lol I'm 5'8" not to short but these bikes sit high to me.
Title: Re: throttle body air filters
Post by: argent brick on September 12, 2012, 11:57:52 PM
I think the K75 s sits a little lower, but I may be wrong on that point. You may want to change over to a low seat version. I am sure there is someone out there that wants to change from low to high. Just look around. Good luck with your project.