400ex jetting prolems. NEED HELP!!

[HondaRacing23]

This is what i have 2000 400ex with a k&N air filter, no holes in air box. lid is on. K&n jet kit with needle. FMF Powercor 4 slicener and powerbomb head pipe. I have jetting this the way the directions told me to and it ruins like SH$%. I have used every jet I got with the kit and put the needle everywhere. tried the same thing witrh 2 different Keihn carbs and same thing. My shop tells me what to do and it doesnt work. Does anyone have the same thing I do if so what are u running? Thanks...

[coryatver]

Did you adjust the air mixture screw?

[cals400ex]

for keihin jets, i would use:

155 main
stock needle location
42 pilot
2.75 turns out on the fuel skrew

for dynojets, i don't have enough experience with them to comment on. make sure you don't have an air leak on either one of the carb clamps. also, is your throttle cable adjusted properly?

[ill_lil_romey]

Start back at the stock setup and then work from there. With the mods that you have you should be ok running anywhere between a 155-165 main, 42 pilot air screw 2.5- 3 turns out depending on elevation. Start from stock and work from there, and remember to move in small incriments.

[HondaRacing23]

Will the keihn jets work just as good as a dynojet kit. Can i use the dyno jet needle instead of the stock?

[cals400ex]

i am not positive, but i think you are suppose to use dynojet needle with dynojet mainjets. i would go ahead and give it a try and see what happens though. tell us what jetting you have right now. we want to know your main, needle location, pilot size, and fuel skrew location.

[HondaRacing23]

Right now I am running a 142 main 42 pilot and the needle pos. is on the 3rd. there is black stuff coming out of my header with the silencer connects.what could that be from?

[HondaRacing23]

Those specs are with a K&N Jet kit too.

[hondarider2006]

I got the dyno jet kit, and it said to put a 146 mainjet in....plug was white as snow when I did a plug test. I ended up using a 165, clip on the 3rd, and 3 1/2 turns out on the mixture screw. I am going to put a 42 piolet jet in soon. Hopefuly it will make it easier to start!

[HondaRacing23]

Is there a difference between a Dyno Jet Kit and a K&N Jet Kit? Or are they both the same thing basicly. which one would u recomend?

[cals400ex]

they are the same thing. i recommend buying the individual jets so you don't have numerous jets laying around that you don't need.

[Doibugu2]

Originally posted by HondaRacing23
Is there a difference between a Dyno Jet Kit and a K&N Jet Kit? Or are they both the same thing basicly. which one would u recomend?

They are both the same.

I have the HMF pipe with lid on and I'm running a 142 DJ, 42 pilot and pretty sure clip is 2nd from the top, or whatever the instructions say.

Have you changed your plug recently.

It sounds like you have an exhust leak it black stuff is coming out of the header. Tighten it back down.

[HondaRacing23]

OK thanks guys ill try that. I put some high temp silicone on there and i thinks it wokring. i have change the plug so i think its all good now. the plug is still really black is that normal or should it be a brownish color? thanks again.:D

[hondarider2006]

It should be a a tanish color. brown/tan should be in the ball park. Black is rich, white is lean.

[cals400ex]

Originally posted by HondaRacing23
Right now I am running a 142 main 42 pilot and the needle pos. is on the 3rd. there is black stuff coming out of my header with the silencer connects.what could that be from?


there is an exhaust gasket that goes on the end of the header. many times you won't notice it being there in the stock system because it is stuck inside your silencer. it is made out of a soft lead material i think. you can get this from you local honda dealer.

[HondaRacing23]

well what should i do to get it to not be so rich. i have tried every jet i got with the jet kit and its still black eer tanish. i did what the k&n directions said an everything? im stumped..

My plug has never been the brownish color. It's always been on the dark side but the quad runs just fine. I go by what the motor tells me. it's either draggin but and stumblin or backfiring. I've never even done a plug check. Plus the writing on the plug is in Japanese or something so i can't read it anyway..:huh

[RIDER11X]

Here is the way I do it. I put in a main that is too big as a starting point and run it through full throttle to make it stumble or cut out. Then one by one I go down in size till the stumble disappears. The same can be done with the needle for the mid range.
Then I lean the feul screw if there is alot of popping on deceleration. I don't read the plug at all.:cool:

[HondaRacing23]

i have tried the plug thing too and i just go by the sound of the motor too. i have tried starting high and goinmg down and still cant get it right? i think im just going to keep it where it is. It wont blow up the engine or anything if it isnt right will it? i think its running pretty good myself i think i need someone to ride it and tell me. thanks guys:)