re jetting?

[SLSD400exGUY]

i just got a new k&n air filter on my 05 400ex and since i put it in my quad will start and then stall. i was talking to my friend and they said it might have to be re jetted. anyways i tried to start it yesterday and it started fine and then it was about to stall and i reved it a bit to keep it going but it stalled. i thought the idel might have to come up a bit? then i tried to start it again and it back fired. anyone have any suggusetions on whats wrong???

[nosliw]

you NEED to rejet. i dont know what jets to put in for just that though. when i got mine and started it, it did the same as yours. i was waiting on an hmf pipe in the mail so i said screw it i'll rejet once i get everything on.

i suggest getting an aftermarket exhaust before you get your jetting right. i mean, why go through the trouble of trying to get it jetting correct when in a little bit you'll be tired of the power and want a pipe and need to jet AGAIN?

just my .02

[SLSD400exGUY]

yea my friend said to re jet when i get a new exhaust too soo im not sure what to do yet and then he said to get a jet kit that way i have a bunch ya know?

im not sure yet but ill figure something out.

thank for the info tho