Running No Airbox

[rooster300ex]

I'm running a k&n with an outerwear and my stock 300ex airbox with no lid. I prolly have to clean it about every 6-8 rides. I was thnking about gettin rid of the airbox. Could I bump the carb settings up a bit if I ran no airbox with a prefilter??

The reason I'm tryin to get some more power is cuz this dude with a 400ex with a pipe and kn is running his mouth. Anyways I can hang with him to the top of 4th gear in a drag, and i wanna show him up. Oh yea he is about 160lbs and i'm like 230lbs and still able to do this. lol any thoughts??

[atv fan 28]

6-8 rides? If i were you, i would clean the filter after every ride.

You might do some gearing changes and do a little better against him, but he will still beat you.:(

have to have airbox

[rooster300ex]

Originally posted by atv fan 28
6-8 rides? If i were you, i would clean the filter after every ride.

You might do some gearing changes and do a little better against him, but he will still beat you.:(

I check my air filter all the time. With a prefilter it doesn't get that dirty. Cleaning it after every ride is alil over kill to me.JMO Sometimes I do clean it before 6-8 rides depends if it gets dirty.

[fearlessfred]

Originally posted by BALLER440
have to have airbox
x2

[rooster300ex]

Originally posted by fearlessfred
x2

What i'm askin is would I be able to bump the jetting up if I ran no airbox, just for a short time

[rooster300ex]

Originally posted by BALLER440
have to have airbox

No ya don't. Alot of people run no airbox.

[fearlessfred]

Originally posted by rooster300ex
What i'm askin is would I be able to bump the jetting up if I ran no airbox, just for a short time i would imagine you would have to rejet. let me explain why i disagree with running no airbox. the carb draws almost all the air from the outer edges of the airhorn.(u could place a silver dollar vary close to the center of of the airhorn before effecting flow ) when u put a filter right on the carb it has a negative effect on flow, because the shape leaving the airhorn does not get progressivly bigger ,like the shape of the air boot.the ultimate shape leaving the air horn,would be that of a velocity stack,but there is no room for that,so the factory did the best they could for the room they had. it would be interesting to see on a dyno what the differances are, but i beleive any gains would be imagined.

[atv fan 28]

Fred, Do think running a 4 inch tube off the carb to a filter is better than running a filter straight off the carb.

Here is my setup.

[fearlessfred]

hi wayne,from what i read in 3 part series that harry klemm wrote years ago,neither setup would be better than stock .the size needs to increase after leaving the air horn. sorry

[atv fan 28]

Originally posted by fearlessfred
hi wayne,from what i read in 3 part series that harry klemm wrote years ago,neither setup would be better than stock .the size needs to increase after leaving the air horn. sorry
Then why does running no lid a stock quad, perform better? The size is not increasing. But everyone will agree it runs better with no lid.

Then why wouldnt it run better with the whole airbox removed.

[fearlessfred]

no one would disagree that they run better with the lid off ( when jetting is corrected) the factory design is to keep the cleanest air coming into the airbox and also to make it thru a 6 month warranty,and that is restictive by design. if u ran a filter at the end of the stock air boot it would run the same as a open box.but running a round tube ,basicaly the same size as the airhorn to the airfilter is restictive. i didnt want to post this next part because i didnt want to get into disagreement with our resident engineees (no insult ment) ,but here we go anyways. air passing thu a cylinder shape of any distance starts swirl like the water going down the drain in the bath tube and that becomes restictive, look at the shape of an air boot on any on any performance atv or dirtbike ( in cars they have the luxury of way oversizing the tubes ) . also look at ports on performace car heads ,never round . when round shapes are used in the intake track ,the opening become progessivly bigger until they are not round anymore.the ultimate shape leaving the carb would be a velocity stack,but there is no room for that. i welcome anyone who is more schooled than myself to explain this better

[fmftrx300ex]

d*mn this is a disapointing post considering i was going to run a straight filter on the carb of my lt250r looks like im goin back to the box unless theres some benifite for 2 strokes tht wasnt mentioned and i dont think a 300ex airbow will realy affect jetting to much compaired to no lid the lids leave a pretty big area for flow when there off

[fearlessfred]

Originally posted by fmftrx300ex
d*mn this is a disapointing post considering i was going to run a straight filter on the carb of my lt250r looks like im goin back to the box unless theres some benifite for 2 strokes tht wasnt mentioned and i dont think a 300ex airbow will realy affect jetting to much compaired to no lid the lids leave a pretty big area for flow when there off what hell go ahead and try it and then give us feedback on how it worked for u. ( im not being a wise *** ),

[fmftrx300ex]

will do and ill let you all know how it works

[fearlessfred]

Originally posted by fmftrx300ex
will do and ill let you all know how it works cool,im interested in knowing what direction u have to go to correct jetting. u would think u would have to fatten it up, but im not so sure about that.i thinh its going to blubber on the topend

[quadrider2112]

you will have to fattin it up but you wood get more from boring your carb your carb can only suck so much air unless u make it bigger. Gettin more air in doesnt exactly mean more power you also need more flow out gettin air in doesnt help u unless u get it out the tail pipe.

But an ex is only gonna do so much if you 230. my best advice is get a 450

[fearlessfred]

Originally posted by quadrider2112
you will have to fattin it up but you wood get more from boring your carb your carb can only suck so much air unless u make it bigger. Gettin more air in doesnt exactly mean more power you also need more flow out gettin air in doesnt help u unless u get it out the tail pipe.

But an ex is only gonna do so much if you 230. my best advice is get a 450 when u say that u have to fattin it up,is this from experance of not running an airbox or is it what u are assumming

[quadrider2112]

im assuming but it should stand to reason.

[kfx400rider03]

on a 300 im not sure how much it helps but look up "fuel atv" air filter set up for the 450's. it cost alot for a filter set up but seems worth it. and i did a cheaper way buy taking a 400ex filter and pipe to the stock intake boot on my ltr. and there was a dyno chart of someone dooing it and showing about 1.5-2 hp gain over the stock box with lid off. i cant remember where i found the dyno chart at tho.

[fearlessfred]

that setup seems like the way to go.i would not recommend removing the stock airboot to anyone and i would love to see dyno run of the esr airbox eliminater verses a stock box with the lid off. i do not beleive for a second that there is any gains.it does look good tho, and i dont mean to offend anyone who has one.

[BM@Ronayers]

Hey Atv Fan 28, what tube are you using? I am trying to do the same to my 300.

[fmftrx300ex]

Originally posted by quadrider2112
you will have to fattin it up but you wood get more from boring your carb your carb can only suck so much air unless u make it bigger. Gettin more air in doesnt exactly mean more power you also need more flow out gettin air in doesnt help u unless u get it out the tail pipe.

But an ex is only gonna do so much if you 230. my best advice is get a 450

also reeds port work and a pipe so i think ittl help more then hurt

[quadrider2112]

reeds? last time i looked 4 strokes dont have reeds!

[fearlessfred]

Originally posted by quadrider2112
reeds? last time i looked 4 strokes dont have reeds! u never no ,a set of reeds and a red powerband and your four stroke will be hauling butt

[atv fan 28]

Originally posted by fearlessfred
u never no ,a set of reeds and a red powerband and your four stroke will be hauling butt

4-strokes wont run right if their flux capacitor isnt working right. Here is a pic of a properly working one!

http://i51.tinypic.com/5xv621.jpg

[fearlessfred]

Originally posted by atv fan 28
4-strokes wont run right if their flux capacitor isnt working right. Here is a pic of a properly working one!

http://i51.tinypic.com/5xv621.jpg
i wonder if a flux capacitor will help on a two stroke. I know i replaced the muffler bearings on mine and helped,and i also changed the red tail light oil to 10/40 and it stops on a dime

[kfx400rider03]

porky pine seat covers?

[quadrider2112]

heavy duty blinker fluid will help with the stopping but if you really want your 2 smoke to go your gonna need 2 cams and some valves.

[fearlessfred]

Originally posted by quadrider2112
heavy duty blinker fluid will help with the stopping but if you really want your 2 smoke to go your gonna need 2 cams and some valves. man , im behind the times, i dont even have blinkers