# Airbox ?



## moonpie02 (Sep 15, 2009)

How many people are running their 750 Brute W/O the metal screen over the carbs? Wondering about removing before jetting the carbs.It looks like a big restriction on air flow.Will it make a diff. when jetting?


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## 08GreenBrute (Jul 13, 2009)

i don't have mine in and haven't for a long time. there are a lot of people on here with it out. the only thing it does is a backfire screen


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## Polaris425 (Dec 16, 2004)

+1, -screen.


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## drtyTshrt (May 27, 2009)

+2 - screen


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## Guarino113 (Oct 3, 2009)

i dont have mine either


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## NMKawierider (Apr 11, 2009)

Mine's out too. Drilled all the holes out first, then took it out completely. Made a difference. Just don't jet it too lean so it backfires. Filters hate fire....


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## moonpie02 (Sep 15, 2009)

I figured I'd take it out especially since I am playing with the jetting.Thanks Guys,Moon.


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## Huntersdad (Nov 12, 2009)

Guys,

What about porting the Airbox? Can this help with major elevation changes? I ride in the mountains and I encounter my 2002 650 bogging down.

thanks,

Huntersdad


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## wood butcher (May 11, 2009)

mine is out also


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## phreebsd (Dec 16, 2004)

mine too


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## NMKawierider (Apr 11, 2009)

Huntersdad said:


> Guys,
> 
> What about porting the Airbox? Can this help with major elevation changes? I ride in the mountains and I encounter my 2002 650 bogging down.
> 
> ...


You don't want to do anything that can't be undone. The Brure had to have some restriction in the airbox to run right...BUT..I had the same problem so I went to Rocky Mountain ATV and got two TPI slid airbox vents and installed them on either side so I could just take the lid off and slide them open as I needed. Then back closed as I came back down. They say with two, it makes the same change as going down three jet sizes. I can tell you that is very true. Even now that I am jetted for up to 8000 feet, I still go to 10 and 11K often and I still use them then. Here's a pic showing one on one side. Remember, they are not water-tight, so if you go deep, don't do this.


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## Bootlegger (Dec 18, 2008)

Mine is in....but I have mine jetted for it.


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## 650Brute (Dec 18, 2008)

My screen is still in also.


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## drtj (May 3, 2009)

Gone


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## DaveMK1 (Nov 8, 2009)

Gonzo


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## bruiser quad (Nov 6, 2009)

On an EFI model Brute will there be any performance change by taking the screen out?


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## drtj (May 3, 2009)

None that I can think of. It will make it run lean.


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## Guarino113 (Oct 3, 2009)

the computer should compensate and add some fuel i would think. i could be wrong but i know thats how the motorcycles work anyway.


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## 08GreenBrute (Jul 13, 2009)

the EFI on the bikes only compensate for elevation not rich/lean conditions i wish they would though


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## Guarino113 (Oct 3, 2009)

o ok. that is different then.


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## 08GreenBrute (Jul 13, 2009)

i think power programmer had a new programmer called the PC5 and it has an 02 sensor so it can adjust for rich lean conditions


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## jeff700VTWIN (Nov 22, 2009)

took mine out of both prairies a long time ago....the screen was always plugged up with crap and got tired of trying to clean it


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## NMKawierider (Apr 11, 2009)

jeff700VTWIN said:


> took mine out of both prairies a long time ago....the screen was always plugged up with crap and got tired of trying to clean it


Realy....Like what? What do you run for a filter?


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## jeff700VTWIN (Nov 22, 2009)

that was when i still ran the oem filter, it was plugged up with little pieces of long grass and dust saturated with oil from all the long distance wheelies


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## NMKawierider (Apr 11, 2009)

jeff700VTWIN said:


> that was when i still ran the oem filter, it was plugged up with little pieces of long grass and dust saturated with oil from all the long distance wheelies


Wow...all that got through the OEM filter. Good reason to toss it :rockn:


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## jeff700VTWIN (Nov 22, 2009)

ya man, all kinds of little seeds and stuff from riding in old hay fields that havent been farmed in years, i couldnt believe the crap that got on to the screen


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## Guarino113 (Oct 3, 2009)

if all that stuff gets on the screen you might want to leave it in there. that stuff aint good to get in the motor


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## NMKawierider (Apr 11, 2009)

guarino113 said:


> if all that stuff gets on the screen you might want to leave it in there. that stuff aint good to get in the motor


I was just thinking that the screen was catching the big stuff like seeds and hay, but what about all that dirt and dust it didn't catch. I'd hate to see your cylinders. And what was the filter doing for him anyway?


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## 08GreenBrute (Jul 13, 2009)

i don't think your air filter was on correctly because you shouldn't be getting anything through it. the screen is only a backfire screen not a secondary filter


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## Guarino113 (Oct 3, 2009)

08GreenBrute said:


> i don't think your air filter was on correctly because you shouldn't be getting anything through it. the screen is only a backfire screen not a secondary filter


i agree


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## jeff700VTWIN (Nov 22, 2009)

well i havent had any problems with my carbs or anything, i have switched to the uni air filter


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