Plastic Air filter cover

[protomatrixkid]

Recently I decided to open up the seat and take that plastic cover off that covers the air filter on my 06 trx250ex. When I rode I noticed a big difference in sound and maybe more speed, and to me it seems like it runs smoother, not choking for air while idleing. I was wondering if in anyway is this hurting my quad?

[DJR300ex]

your air box lid restricts a lot of airflow, taking it off lets in a whole lot more air. i would recommend leaving it off and rejetting your carb for the extra airflow, unless you ride in a lot of water, then i would say leave it on. you dont want any water in there

[honda300EXtreme]

yea,, opening up the airbox allows alot more airflow.. so i would bump up the main jet a size or two... if you ride in alot of muddy conditions i recomend looking into an airbox cover..

EHS racing makes a nice one although im not sure they make them for the 250

[protomatrixkid]

sorry im real new to this, but do you have to buy parts to rejet?, and do you know of a guide or anything to do this?

[honda300EXtreme]

its cool... to rejet all you have to do is buy the size jet you need... for just removing the lid i would just bump up 1 size...

then remove your old one and install it (in your carb)

ill see if i can find you a post that goes full into detail on jetting...


and a reapir manual for your bike isnt a bad idea either...

[protomatrixkid]

thanks, but can you tell me what exactly one size from sock is called, so i can google it or something, or order it.
thank you for the help

[honda300EXtreme]

thats what im trying to think of... i wana say the stock main jet is a 90.. but dont quote me on that...

just do some searching on here you'll find a ton of posts that go into detail or if i get a moment ill tell ya... trust me its not difficult..


jetsrus.com sells jets

[protomatrixkid]

thanks man, yeah ill just search best i can

[mx825]

stock main is 95. bump it to a 100 or 102. &read the faq, it's really helpful;)

[protomatrixkid]

thank you, ill probably just buy a 100, is there a way to check the a/f?

[07250ex]

Originally posted by protomatrixkid
Recently I decided to open up the seat and take that plastic cover off that covers the air filter on my 06 trx250ex. When I rode I noticed a big difference in sound and maybe more speed, and to me it seems like it runs smoother, not choking for air while idleing. I was wondering if in anyway is this hurting my quad?

Well depending upon where you live it is summer time (at least where i live) and in the summer the air "richens" ur bike out because off the hotter air so when you take ur lid off especially for the first time in the summer you should notice a huge difference especially if ur jetting was stock or not spot on.

welcome to the site and you'll learn a whole lot here trust me

[mx825]

Originally posted by protomatrixkid
thank you, ill probably just buy a 100, is there a way to check the a/f?


trial and error- spark plug also helps.

[Honda10]

Does anyone have any experience with the Outerwears Air Box cover, does it a big difference?

[450rJam]

buy a jet kit, it will come with a range of jets (usually 10-12 jets)
that way you will have them if you deside to add exhaust or other mods or if one size up isnt enough (2 quads with same exact mods may not take the same size jet)

yes leaving the lid off will let it run better but it will be running lean (too much air to fuel ratio) which can make your motor run too hot or burn up your piston/rings

alot of info on this site but a service manual will help you alot