Air filter for mikuni carbs

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lammy1
Posts: 8
Joined: Mon Nov 27, 2006 12:00 am
year: 0
Location: the Netherlands

Air filter for mikuni carbs

Post by lammy1 »

Hello all,

christmas is an ideal time to work on my Paso.
Now I have plenty off time for it.

For my Mikuni carb conversion I am searching for air filters.
Many say use K&N filters.
How about foam filters like these below.
I use them on my race scooters.

Image

Image

thanks
Frank
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Finnpaso
paso grand pooh-bah
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Post by Finnpaso »

I think, most important are diameters, not brand, cause near all are "enough good"... :evil:
Antti http://www.youtube.com/watch?v=HeKOh3XoXPg&NR=1
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Fraser
Posts: 334
Joined: Tue Jan 17, 2006 12:00 am
model: 750 Paso
year: 1986
Location: Lower Hutt, New Zealand

Post by Fraser »

Frank,

Foam pods work just fine as long as the diameter is correct. I used Unifilter pods for the Mikunis, type PK79, refer to http://www.unifilter.com.au for more details.

Fraser.
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ducinthebay
paso grand pooh-bah
Posts: 1323
Joined: Sat Sep 03, 2005 12:00 am
model: 750 Sport
year: 1990
Location: SF Bay Area

Air filters

Post by ducinthebay »

If at all possible, add a bit of length between the air cleaner and the carb. It vastly improves low end performance and torgue. There's a phenomenon called fuel fog that comes back out of your carb at lower rpms. If you don't contain it, it becomes a variable mix creating some odd behaviours that are difficult to identify. Adding just a few inches of intake trakt improves the bottom end mixing. This is one of the functions of a stock airbox. Race bikes don't use this because they are never using the low end, but a street bike does all the time. I added some 2" (50mm) rubber elbows to my Dellortos and it improved the idle and low speed drivability alot. I bought them from http://airflowonline.com/ , the part number is 90HL2 Rubber Intake Hose 90 Degree 2" There is plenty of room for 6" long filters after you put a 90 elbow on. I figured that there wasn't much restriction since the elbow was 50mm, the carb was a 36mm, and the intake valve is what, a 34mm? The longer boot also helps in creating laminar flow, which also helps carburation in the mid range and top end.

I have 36 Dells with the short grey plastic screw-on velocity stacks (bells), just right for the 2" rubber elbows. I put some 6" UNI foam filter pods on top of those elbows using some 2" aluminum sleeves as joiners. They stick up into the area under the tank where the stock aircleaner used to be. Hope this helps.

Foam filters do a fine job, especially the new two stage ones. Heck, desert racers have been using them for years. The only problem with foam filters is backfiring. One good flame will melt them down to nothing. Use a synthetic filter oil like No-Toil, and it should suppress the flames a bit, if it everhappens.

Cheers, and happy new year.
Duc in the Bay
1990 750 Sport x2-Rosso Blanko (900ss copy) & Nuovo Nudo (Scrambler project)
1991 907 -mostly stock
2002 ST4s - Lots of mods.
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Fraser
Posts: 334
Joined: Tue Jan 17, 2006 12:00 am
model: 750 Paso
year: 1986
Location: Lower Hutt, New Zealand

Post by Fraser »

Hey there ducinthebay.
Have sent you a PM, about a 450 RT, but never sure that method works. If you do not receive anything please provide your email address so I can contact you, thanks.

Fraser.
ducapiero
Posts: 178
Joined: Mon Dec 11, 2006 12:00 am
model: 750 Paso
year: 1985
Location: Italy

Post by ducapiero »

Hi cause i have to buy it after the mikuni conversion what dimension have to have this filters i choose the cotton one not these of foam...i bought two for car but they are too big! :screwy:
they didn't enter under the tank...
many thanks
:D Piero
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