kn filter

[whc]

am getting a k and n air filter wondering about running with out the air box lid and maybe remove muffler baffle (stock exhaust)_is there any power to be gained by doing these changes?? will I need to rejet?? questions questions is it even worth bohtering with?? Mild Bill

[bigballz400]

run lid off and dont take the baffle out a buddy of mine did that and burned up the valves

[honda729]

you always need to rejet to get the optimum performance, and for 5 bucks and 10 min to change its not that big of a deal. you might want to invest in an outerwear if your not going to run the lid

[Exrider434]

Originally posted by honda729
you always need to rejet to get the optimum performance, and for 5 bucks and 10 min to change its not that big of a deal. you might want to invest in an outerwear if your not going to run the lid

definately invest in the 15 dollar outerwears. I didnt and now im paying hundreds for the motor i messed up

[chris_bchs2007]

yeah i feel you on the outerwear thing... ive gotta rebuild the whole top end the 400 i just bought b.c the kid didnt keep one on it.... i mostly trail ride so im gonna go with uni

[whc]

good info guys, but why the uni instead of the kn, also how restictive is the stock filter???? makes me think I might better leave things alone unless there is a noticable power gain Bill

K&N is great with an outerwears! If your running open air box lid though invest in the outerwear air box cover also.

[madmax400ex]

Just wondering how well the outerwears work? I have been considering running without a lid, but i trail ride and i am afraid water and stuff will get through the outerwear.

Originally posted by madmax400ex
Just wondering how well the outerwears work? I have been considering running without a lid, but i trail ride and i am afraid water and stuff will get through the outerwear.

I rode my 400ex through hurricane type rain it was coming down so hard it felt like needles even when you werent moving. Anyways I was flying around hitting huge puddles water and sand/mud is spraying everywhere it was real fun. I realized oh no i'm running open air box lid! I quickly jump off and take off the seat to look to see how bad my airfilter is caked with sand and is soaked with water. To my surpirse there was not a drop of water that went past the outerwear and the sand/mud stuff would either stick to the outerwear or just fall right poff of it and nothing got in. After that I had all faith in my choice of airfilter and I continued to ride because nothing went throught he outerwear, now hitting some really deep water and that spashing up I would put the outerwear air box cover on also for added assurance against the elements.

[madmax400ex]

Originally posted by FoxHondaRider
I rode my 400ex through hurricane type rain it was coming down so hard it felt like needles even when you werent moving. Anyways I was flying around hitting huge puddles water and sand/mud is spraying everywhere it was real fun. I realized oh no i'm running open air box lid! I quickly jump off and take off the seat to look to see how bad my airfilter is caked with sand and is soaked with water. To my surpirse there was not a drop of water that went past the outerwear and the sand/mud stuff would either stick to the outerwear or just fall right poff of it and nothing got in. After that I had all faith in my choice of airfilter and I continued to ride because nothing went throught he outerwear, now hitting some really deep water and that spashing up I would put the outerwear air box cover on also for added assurance against the elements.

Thanks for the advice. One more question - Where is a good place to buy them?

Originally posted by madmax400ex
Thanks for the advice. One more question - Where is a good place to buy them?

rockymountain used to be the cheapest, not sure if they still are or not.

[Hondamaster5505]

Originally posted by bigballz400
run lid off and dont take the baffle out a buddy of mine did that and burned up the valves

thats bullcrap. It DOES NOT affect the valves in any way. If that were true, then aftermarket exhaust's would burn them up like crazy because they're ten times the flow.

[ONAGER II]

Originally posted by Hondamaster5505
thats bullcrap. It DOES NOT affect the valves in any way. If that were true, then aftermarket exhaust's would burn them up like crazy because they're ten times the flow. i agree, thats crap. your buddy obviously didnt burn up his valves because of his exhaust pipe. maybe if his fuel mixure was a tad bit lean... maybe he installed some syuff and didnt jet it. alot of factors will burn up your valves.