jetting ? on a 400ex

[sica]

hi, i am new to all of this so i need some help....ok this is what i have ....
on a 2003 400ex i got a dmc alien exhaust,white brothers rev box,k&n filter,and a dynojet kit....the instructions based on where i live told me to put the 146 jet in witht the clip on the 3rd position and turn the screw on the bottom of the carb all the way in and then out 3.5 turns.....i did this and it was running lean... so i went the other route...it said for stage 2 remove the air box lid and put the 170 in so i did and the spark plug is still white......so i took the 170 out and put in the 155 that came with it and put the lid back on and still lean....my ? is what is the screw on the bottom of the carb that i had to turn does it controll aht air(if so i need to turn it in a bit) or does it controll fuel(if so i need to turn it out a bit).....PLEASE HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[hondarider2006]

well first off how did you do a plug test? You have to do it wide open, hold it there, pull in the clutch and shut it off. Don't let out the clutch untill you have come to a complete stop also. Ride it for about 15 minutes and get it warmed up also. I am running a 165 with the lid on, but right now its only 55 above....(winter is coming:( )

[cals400ex]

are you sure you just don't have enough time on it yet to see if your running lean or rich with your new mods. you also need to find out if your running lean with pilot or mainjet, thats if your lean at all. i bet your lean with your pilot jet. i would put in a 42 pilot jet and turn the fuel skrew out 2.5 turns or so. the fuel skrew is small adjustment for the pilot jet. it is a fuel skrew, so turning it out richens the mixture. however, this fuel skrew and pilot jet are only used for about less than 1/4 throttle. how did the bike run at full throttle with the 146 in? how about the 170? i would think 170 is definately too big even with the lid off. however, i would think that 146 is too small even with the lid on.

[sica]

i was testing with riding at wide open throttle pulling the clutch and then shutting it off and coasting to a stop....and as far as the pilot jet the kit says nothing about them it is just main jets.......i also tried to move the e-clip down to the 4th slot on the needle with the 146 but that made it run way toooo rich so im kinda lost at this point

[cals400ex]

the 146 main should be too small. i would put in a 42 pilot. try your needle in the stock position. you may be getting a rich setting from the needle in the 4th position. try the 155 main. i am not sure on the main since you have the dynojet kit. a 155 is just a guess. i don't think there is too much difference between the dynojets and keihins jets, but there is a difference.

if your plug was white when you started and only changed needle position, i would bet thats your problem. is the bike running like crap? if so does it run like crap on low throttle positions or full throttle?

[dariusld]

How does it RUN with the way the jet kit said to do it?

[sica]

both times good.... but they were both lean.......i just tried to turn the fuel screw out a little more and it did not seem to do anything i have the 155 jet in right now with the clip on the 3rd slot and 3 1 inch holes drilled in the air box.........is there any air fuel gauge made cause the whole looking at the spark plug thing just doesnt seem to be working

[tprender]

It sounds like you are giveing the numbers for the stock carb jets. I though that the dynojet kit had jets and a different needle with a different set of numbers.
I think that moving the clip is a bout the same as changing the pilot jet one size I think or close to one size. Go to what the dynojet kit said and start over.

[cals400ex]

as of right now, you have tried the 146,155, and 170 mainjets. you should have noticed that the bike runs a lot better with one of these jets in over the other two. there is a pretty big difference between those jets. as far as the fuel skrew goes, it won't make a difference in full throttle. it is for less than 1/4 throttle.