ìm wondering what the K & N filter do if you have 2003 trx 250ex, Does it make it go faster ?

 

If you look at the end of the snorkle on your 250, you will notice that the hole in it is about the size of a nickle!! This is the limiting factor in your air intake. So, if you add a K&N, without venting the airbox, you are pretty much wasting your money. I vented the airbox with about 6 of the White Bros 1" airbox vents, a K&N, and an FMF MegaMax II silencer, and of course a rejet. It made a noticeable difference in power. But, with the airbox vented, it is no longer waterproof!!

 

You could always buy one of those vented covers and keep yours stock so you'd still have a sealed one

 

You could do that but then you'd need to rejet everytime you switched back and forth...that's definatly not worth it to gain the few more inches of water fording capability....just take your cover off and rejet.

 

I bought a K&N for my son's 250ex, was not too impressed with it. From idle to full throttle it was very weak. With the stock air filter we could bring the front end up on it, with K&N we could not. I talked to someone about this and he told me to try a UNI filter, I did this and it works fine now, pulls the front end right up !! We did all of this after we jetted out the carb.

 

um what do u mean to rejet the carb what do i do im new at this atv stuff what do i buy and how much is the white bros thing u mentioned with the white bros trhing and the K & N filter what does that help do to ur quad what does it imoprove well reply if you can

 

ok rejetting is basicly adjusting youre fuel to air mixture. there are "jet's in youre carb a main which handle's mixing youre fuel and air. from middle to open trottle and a pilot that also handle mixture from bottom to just below mid range, and also control volume of gases next there's the "clip" this is what youre cable connect's to it control's the oping and closeing of the carb. via an "air needle" the clip it is mounted to has diffrent notches that control the amount of volume of air and fuel this air needle might need to be moved eirther way acrossed the clip the "jets" whitch look like little brass plug's with hole's drilled in them may and most likely will need to be replaced with a larger size noone has any exact spec's for jetting if you buy a k&n kit it will most likely have everything you need alot with some helpful advice. the vent's the other guy spoke of go in youre airbox you drill hole's in it and insert these vent's they alow a large gain in airflow without leaveing youre filter completely exsposed like running no airbox. if you intend to be in the mud i recommend this highly. if not running no lid clearly give's you more airflow and is the hot setup for racer's and hardcore rider's around the world....well i hope this helpped you out peace

 

I would not spend the money for a pipe, you get VERY little power increase. just not worth the 300 or more.

 

Greetings fellow mud person
The K&N air filter will give you about 10% more power. This does not convert into a faster top end speed but you will get to your top end speed faster.
There is a chart showing you the differences in air flow from stock to K&N air filters. Check it out at www.atvtires.com[img]i/expressions/face-icon-small-wink.gif[/img]

 

A 10% gain in HP? If if it's in writing it must be true? Hmm...wonder who's chart that is.