Airbox lid or not??

[rhandw69]

How much does running with the airbox lid on or off really affect the performance of the bike.
Its winter or fall, and I usually ride without it in the summertime, but in wet conditions id like to put it back on.
How will this affect the power, will it be major or minor??
Thanks
Rhan

[Atomic83]

If you take the airbox lid off you will probly have to rejet. You should notice a little power increase. Make sure you use an Outerwear on the filter if you run w/o the lid.

[nakomis0]

The only way to ride a 400ex is with the airbox lid off. Unless its wet of course.:)

[trx400ex]

does anyone else notice its louder with the lid off when your sitting on it but not if your just listening to someone ride around on it

[wyndzer]

Yes it will be slightly louder. Take the lid of the the air box on your car, it will also be louder. Try it!!

[kabd69667]

I would just drill holes in your airbox, on a dyno test at http://www.geocities.com/gtthunder.geo/ (thats gt thunder)
It actually takes hp. away. Here is the chart

[400exJOE]

I think the reason you lost a little power was because the quad was probably running a little lean and needed a slightly larger jet.

[400exBro]

If they jetted then it might run a little better then stock but i dought you'll notice a difference i didn't at first with out the pipe and stuff. It is a little bit louder and you do acclerate bit faster than stock but you mess up the plug to because of inpoper jetting and it won't start after a while!! I've tired on a stocker if you got any qusetion just give me a hoot.
Also if you want some power get a pipe K&N filter jet the carb lighter pistion bore out 16th tooth sporket and some other goodies
lata
400exBro

[Tommy 17]

rh buy a outwears air box cover for 18.99 it stops mudd, water and dust just like the cover but air can pass throught it. when i was stock and i took off my air box cover it seemed like it had more low end but it did die out very quick at the top not like it is now. i mean stock nuttin done the way it came off the show room.

you will have to rejet if you remove the lid,,,no if ands or buts about it,,,you have too....I have 7 -- 2 inch holes cut in my airbox lid. I've heard that running with the lid off will not create the correct vacuum in the airbox,,don't know but that's what I've read and that it will not make the bike run better than just modifying the airbox lid,,,,like I said I read that somewere,,DW,,ATV sport or something..

[FlyinRed]

LOOSE IT. The only time I've had a problem with water is running through a river at high wheel speed.

[4punksdad]

I couldn't fit a vacuum in my airbox, so I did this.

[Tommy 17]

gess 3 punks u got the most highly modded air box lid i have seen yet what all that stuff on there i see the lid, outwears cover and sometin else. whats the white stuff on there.

[4punksdad]

thats my idea of a rain coat :D

fabric layer sprayed down with scotchgard.