400ex carb fuel mixture adjustment question

[uchi]

just a quick question or two. on my 03 400 ex i want to add a bit of fuel, it seems to be a bit poppy on decel and i wanna see if i can just add some fuel without having to rejet just yet. so my question is this. is the screw i need to turn the one that sits right near choke handle? its a large diameter screw with a cable coming off the back of it. is that what needs to be adjusted? also which way to add mroe fuel? id imagine i have to run it out as if im unscrewing it. and will it only turn x amount of times before it stops or do i need to close it fully and then open it from there counting the rotations? thanks for reading. :)

[dariusld]

old thread

[sheldo]

so my question is this. is the screw i need to turn the one that sits right near choke handle? its a large diameter screw with a cable coming off the back of it
no that is the idle screw the air screw is under the carb in front of the floatbowl try turning it out

[uchi]

sweet thanks guys. can i get to it without removing the carb?

[BassHunter0123]

it is possible but you will need a really short screwdrive or a special tool. it the screw dont work bump the pilot up one size

[uchi]

will do. but wouldnt i need to bump the main up if its popping under decel?

ive got some small stubbies i shold be able to fit in there. id like to avoid having to rejet this carb as id like to do the 450r carb swap. its sitting here waiting to go in but ive been riding 3 times in the last week so i dont think its happening this year :D

also that screw, will it bottom out while i unscrew it or just fall out?

[dariusld]

Originally posted by uchi


also that screw, will it bottom out while i unscrew it or just fall out?

Will bottom out and fall out. Adjust by bottoming out then 2.5 turns out and start from there. You could count the turns in till seated to see where its at now.

Exhaust leak will also cause popping besides jetting.

[BassHunter0123]

just put the 450 carb in and get it tuned in. i just git doing it. it is well worht it. has great pull throughout all the gears. you will love it

[uchi]

i think i will. ill see how busy my week is gonna be and then ill start working on it. i hear dbaout a guy whos local to me who races atvs and has an atv dyno in his shop. so im thinking after i get it street tuned to where it runs half decent ill get him to fine tune it on the dyno. :D

also how far out can the screw go before i shouldnt try to twist it out anymore?

[BassHunter0123]

dont go more than 3 if you go more than that get a bigger pilot

[uchi]

Alright thanks for the info guys.