View Full Version : Modified air box?

04-29-2003, 03:52 PM
just wanted to know how some of you have "modified" air boxes... and how to do this mod. i used the search function but came up empty handed.

04-29-2003, 06:01 PM
I drilled 9 holes, 5/16 inch in size, in the air box next to the large factory opening to allow the bike to breathe better with the new larger carb. If you want, I'll take some pics and post them on my website...

-Steve :cool:

04-29-2003, 06:24 PM
steveo what jetting are you using with that setup?

and i would be up for a ride.

ysr star
04-29-2003, 06:43 PM
We usually cut a 2" or 21/2" hole in the airbox right next to the stock air inlet (can't remember how big it is). Make sure all the cutting you do is on the inlet side of the filter, not on the carb side. We have been doing some dyno runs in the past few days comparing the airbox vs. the pod filter on a stock cylinder for comparison. Looks like we can jet leaner for more power and less fuel consumption with the airbox. We will keep you posted on that progress.


04-29-2003, 06:48 PM
ya if you could take some pics and post them that would be great steveo. also Jon are the gains significant at all?

04-29-2003, 07:14 PM
I am running the factory jetting for the 21mm carb. I noticed a wider power band when I opened up the airbox, and also better throttle response. What prompted me to do the mod to my airbox was the bike didn't want to take off from 0 mph...now, I don't have to ram the RPM's to take off. Pretty smooth.

Yeah, I'm up for a ride on the weekends. I work in Columbus and will be starting to ride to work (when the mornings warm up). I left for a ride this evening and ended up going about 1/10 of a mile (to my neighbor's garage where we shot the $hit for a while :D ) You're in Athens aren't ya? This weekend is packed, but next weekend my wife and daughter are off to WVa, so I'm free to ride then if you are!

-Steve :cool:

04-29-2003, 07:54 PM
yeah that sounds like a plan...sundays are good for me...where exactly are you...i am in athens and i have traveled to circleville not a bad ride...i have that problem with the hard to take off so i may try that airbox mod

04-29-2003, 10:03 PM
tommarrow i will check out the air box and see what i can do. Pics would still be nice.

04-30-2003, 02:41 AM
well.... ihave a velocity stack for the airbox but i aint fitted it yet :S

04-30-2003, 04:15 AM
velocity stack ? 8o

04-30-2003, 04:27 AM
Improves air entry into the carburettor and will give a small increase in power. The gain depends on the state of tune of the engine.
<img src="http://www.johnmaherracing.co.uk/jmrshop/shopimages/velocity_stack.jpg" style="border:0;"/>
Kinda like this.


04-30-2003, 04:42 AM
I'll get the pics up on my site tonight and provide the link...goin' to work now.

I'm just about 25 minutes north of Circleville in a town called Commercial Point. There aren't a lot of twisties around here, but there are a few. The best place to ride (when I had my 600) was down near Old Man's Cave or back roads near Chillicothe. My buddy lives in Wheelersburg and there are some SERIOUS roads there if you can watch out for the coal trucks coming north...

-Steve :cool:

04-30-2003, 10:42 AM
more like this.....

<img src="http://apriliaforum.safeshopper.com/images/br01e7vr.jpg" style="border:0;"/>

Just not billet.... i just need a spare airbox lid... was gonna buy a whole airbox but ijust want a lid.. or a cheap box.... i want a lid as i wanna test all this stuff out.... and need to keep mine...

04-30-2003, 07:06 PM
i had to work all day today so tommarow i will start this project.

Oh ya before i went to work i pulled my first endo, it was pretty tight i held it for about 15 - 20 feet but i have a feeling that this is terrible for the bike to come slamming down in the rear so im not going to do anymore.

I've tried to pull wheelies by revin it up to 8-9k and letting the clutch go but my bike just jerks up about a foot and then drops, might this be a clutch problem or just my ability to do a wheelie? im going to try to stand on the back pegs and see what happens

05-02-2003, 04:40 AM
I don't want to sound like a dick or rush anything... but how are those pics coming along of the modded (drilled) airbox?

05-02-2003, 04:46 AM
I'll have them ready by the end of the evening. We've had some bad weather here that's kept me from working outside. My dig camera doesn't do real well with non-natural light...

-Steve :cool:

05-02-2003, 06:16 AM
roger that, Thank you :)

05-02-2003, 04:59 PM
Ok, the pics are posted on my site now.

www.iwaynet.net/~sbreech/technical.html (http://www.iwaynet.net/~sbreech/technical.html)

-Steve :cool:

05-03-2003, 04:05 AM
aaaaah... Thank you! I would have drilled the holes in the way wrong place <img src=http://www.ezboard.com/intl/aenglish/images/emoticons/embarassed.gif ALT=":o">