2007 honda 400ex hard to start and idles rough

[400exledford]

ok i have a 07 400ex and when i try to start the atv i have to pump the gas to get it start and then once it starts it idles really rough. if any one knows what this might be that would be wonderful. if you need more info just ask.

[01boneless]

bump your piliot jet up to a 42

[fish22]

Yeah the 42 pilot makes starting really easy.
While youre in your carb, go ahead and clean it really good with carb cleaner.

[hocman123]

if its a stock engine u can put a 40 pilot in and it would work fine if u put in a 42 i would turn the a/f screw in a half a turn or so to keep it ftom becomeing to rich

[finsteratv]

Originally posted by hocman123
if its a stock engine u can put a 40 pilot in and it would work fine if u put in a 42 i would turn the a/f screw in a half a turn or so to keep it ftom becomeing to rich
x2...actually with the 42 pilot you could take out the choke too (better throttle response) which is due to increased airflow. then without the choke you give it a few quick snaps with the throttle then fire itt up and start slammin gears.

[400exledford]

ok so here is what i have now now my atv when its cold it idles fine and then onces it warms up it starts popping. would i still need to change the pilot to a 42

[sm00th026]

Originally posted by finsteratv
x2...actually with the 42 pilot you could take out the choke too (better throttle response) which is due to increased airflow. then without the choke you give it a few quick snaps with the throttle then fire itt up and start slammin gears.
Question, when you say take the choke out.do you take the rod out an lever off or just take the the center flap piece out?I have a 250x/350x Hybrid Im running a 400ex carb. with 42/150 jet's. Will this give me more throttle response with what I have.Or should I just leave it alone? And Sorry I don't mean to steal the thread or anything. I just thought I would ask. Thank's!!

[hocman123]

first of u need just to open the carb up and find out what u have in it b/c u might have something to big in it allready and thats why its popong. also u should check the the intake boot is on the engine and the carb tight still and that it has no cracks in it

[finsteratv]

Originally posted by sm00th026
Question, when you say take the choke out.do you take the rod out an lever off or just take the the center flap piece out?I have a 250x/350x Hybrid Im running a 400ex carb. with 42/150 jet's. Will this give me more throttle response with what I have.Or should I just leave it alone? And Sorry I don't mean to steal the thread or anything. I just thought I would ask. Thank's!!
i just took the big butterfly valve out because with the lever you also have to plug the little hole where the lever was.