Whats your opinion......

[QuadJunkies]

We are rejetting my 426ex, it was running WAY too lean, we have a K&N,open air box,Was running 165 when it the temps were around 40-50ish,
We went from a 38 pilot to a 42(they were out of 40 at the time) and went to a 180 We are pretty sure that the pilot is too big and jetting nees to be around a 175 ,but just to test all you jetting Guru's:D , Say, Im riding in 4tthgear, I go to shift and stop and it dies almost all the time:confused: and the idle sounds like it will die unless you keeping blippin the throddle, then sometimes it will idle low then go higher not a steady good idle, would this be due to having too big of a Pilot?? Ive got alot of jets to try and another pilot,just wanted to get all your opinions, neverr had to fine tune my EX before when the motor was stock, the jetting pretty m,uch stayed the same all the time an just ran a little fat ........Thanks!!!

Tina I run a 42 pilot year around. From 20 degrees out to 100 and it runs just fine.

Do you have your flywheel lightened???

[QuadJunkies]

Originally posted by Rico
Tina I run a 42 pilot year around. From 20 degrees out to 100 and it runs just fine.

Do you have your flywheel lightened??? no. I havent...Ive never had to change the pilot before(always had stock) and it ran good,but since the mods were done,we still need to get it dialed in better:)

[Chef]

What I did was went to either Napa or Radioshack-dont remember which one-and bought a handheld temp gun-with a little digital reading. It reads from like 0 or 999 F. My driveway is a quarter mile long, so I would just do like 4 WFO runs, and have someone waiting at one end with the heat gun. Stop right next to them and keep it hot, and check the head temp. Should be somewhere between 230 and 245. Too hot means that its lean, too cold means its rich...seems to have worked perfect so far!

[cals400ex]

i really wouldn't think you would need a 180 main. i ran a 160 in my 10.8:1 406, stage 2, x-6, uni filter, etc. that was in winter with the air box lid ON.

are you running a stage 2 by chance???

[QuadJunkies]

Originally posted by Chef
What I did was went to either Napa or Radioshack-dont remember which one-and bought a handheld temp gun-with a little digital reading. It reads from like 0 or 999 F. My driveway is a quarter mile long, so I would just do like 4 WFO runs, and have someone waiting at one end with the heat gun. Stop right next to them and keep it hot, and check the head temp. Should be somewhere between 230 and 245. Too hot means that its lean, too cold means its rich...seems to have worked perfect so far! Im not running hot anymore, that radar is a TON of money:eek: its just the idle and when I go to stop it dies,this happens reguardless,its not a lean issue I do know that much,funny thing is, I think it ran better when it was lean:eek2: but I know thats not the thing to do either....At least then my idle was perfect BUT.. I have always been curious what Temp I should be running Thanks !!!! Good info to know!!:)

[Chef]

Originally posted by cals400ex

are you running a stage 2 by chance???

Are those stage 2's the kind of cam that just doesn't like to idle? My cam is like that...right when you start it it wont idle but once its warm its fine.

Tina, why dont you just turn the idle screw up? :p

[cals400ex]

yeah, the stage 2's have a problem with idleing. mine would idle fine when cold but not the best when warm. if you lean out your fuel skrew it will idle better. i don't seem to have as much of a problem when i put on my fcr carb. i think maybe the stock needle needed to be replaced with a different one. where i felt it was jetted good with the pilot jet and fuel skrew, it didn't want to idle. that made me believe it was the needle. however, maybe it had something to do with the slide too, who knows. also, it may just not be the stage 2. however, the stage 1 gives my friend no problem at all.

in my 406 i turned my fuel skrew 2 turns out with a 42 pilot jet. my headers didn't glow at idle so it wasn't too lean, but it did pop pretty bad on full deceleration. if i richened up the mixture, the idle was irratic when the bike was warm.

[QuadJunkies]

Originally posted by cals400ex
i really wouldn't think you would need a 180 main. i ran a 160 in my 10.8:1 406, stage 2, x-6, uni filter, etc. that was in winter with the air box lid ON.

are you running a stage 2 by chance??? Yes I am...

[QuadJunkies]

Originally posted by cals400ex
yeah, the stage 2's have a problem with idleing. mine would idle fine when cold but not the best when warm. if you lean out your fuel skrew it will idle better. i don't seem to have as much of a problem when i put on my fcr carb. i think maybe the stock needle needed to be replaced with a different one. where i felt it was jetted good with the pilot jet and fuel skrew, it didn't want to idle. that made me believe it was the needle. however, maybe it had something to do with the slide too, who knows. also, it may just not be the stage 2. however, the stage 1 gives my friend no problem at all.

in my 406 i turned my fuel skrew 2 turns out with a 42 pilot jet. my headers didn't glow at idle so it wasn't too lean, but it did pop pretty bad on full deceleration. if i richened up the mixture, the idle was irratic when the bike was warm. We were thinkin maybe it IS the needle, it ran soooo good when it was cold out ..idle was perfect ran like a raped ape,and still do, but I do feel its WAY too fat.Does the pilot effect Idle and for a sudden stop,or should I say sudden downshifts why does it die? if you dont blip throddle almost all the time, it will shut off 80% of the time.......

[QuadJunkies]

Originally posted by cals400ex
yeah, the stage 2's have a problem with idleing. mine would idle fine when cold but not the best when warm. if you lean out your fuel skrew it will idle better. i don't seem to have as much of a problem when i put on my fcr carb. i think maybe the stock needle needed to be replaced with a different one. where i felt it was jetted good with the pilot jet and fuel skrew, it didn't want to idle. that made me believe it was the needle. however, maybe it had something to do with the slide too, who knows. also, it may just not be the stage 2. however, the stage 1 gives my friend no problem at all.

in my 406 i turned my fuel skrew 2 turns out with a 42 pilot jet. my headers didn't glow at idle so it wasn't too lean, but it did pop pretty bad on full deceleration. if i richened up the mixture, the idle was irratic when the bike was warm. What elavation are you at ??

[QuadJunkies]

Iforgot to mention that when I was lean, it wasnt to the point of glow or popping or pinging, just ran Hot very fast and plug was almost pure white:eek2: so Im glad we looked!!!

[zephead400ex]

Originally posted by QuadJunkies
We were thinkin maybe it IS the needle, it ran soooo good when it was cold out ..idle was perfect ran like a raped ape,and still do, but I do feel its WAY too fat.Does the pilot effect Idle and for a sudden stop,or should I say sudden downshifts why does it die? if you dont blip throddle almost all the time, it will shut off 80% of the time.......

My suggestion would be to raise the needle a notch to lean it out if you think you are too fat. The pilot and needle work together but it does not explain why on downshift the motor will die:confused: By what the other guys are saying, the stage 2 cam could be your "problem" with the motor dieing, but again, I am not sure what the cam.

[cals400ex]

Originally posted by QuadJunkies
What elavation are you at ??



my elevation is 625 feet.

[cals400ex]

forgot to mention, i do have the clip in the 4th position too (one down from stock).

the pilot jet will pretty much control the fuel at idle or maybe up to 1/10 throttle or so. so basically it will control fuel when your not on the gas. yes, it could be the diameter of the needle too. i tried and tried to get an aftermarket needle for the 400ex but i couldnt' find one. i refused to buy the jet kit for just the needle.


also, where you lean at idle, 1/8 to 3/4 throttle or full thorttle?? or did you not do a plug chop at these positions?


i would first try turning in the fuel skrew a 1/4 turn at a time and see if it gets better. this is the only way mine would idle. if your still in the stock needle clip position (3rd position), i would bet money your lean between the 1/8 to 3/4 throttle for sure.

[cals400ex]

Originally posted by zephead400ex
My suggestion would be to raise the needle a notch to lean it out if you think you are too fat. The pilot and needle work together but it does not explain why on downshift the motor will die:confused: By what the other guys are saying, the stage 2 cam could be your "problem" with the motor dieing, but again, I am not sure what the cam.




raising the needle will actually richen the mixture around 1/8 to 3/4 throttle. raising the clip will lean out the mixture though.

[zephead400ex]

Originally posted by cals400ex
raising the needle will actually richen the mixture around 1/8 to 3/4 throttle. raising the clip will lean out the mixture though.

Oops, the clip is what I was referring too:D Thanks for clarifing that Cal!

[quadkrazy400ex]

i have a pro circuit t4 complete system with k&n filter without the air box lid on and im running a dyno jet brand jetting. im running right now a 170 main jet so if you are only running a 165 then you need to jump up..im below 5000 ft

[QuadJunkies]

Im at 2500 ft. I ran a 170(betweeen and it ran very well until I got the motor work done.Thanks Ill try al the above and let you know how it works;) after I get it dialed in Im considering the Flywheel mod, I was told not to mess with it from a Racing Co. but I hear so many people are happy with it...... I did have Dyno Jets ,but when the guy done my motor mods he put in Honda jetting:grr:

[Colby@C&DRacing]

I hate to say it but I TOLD YOU SO . I remember some one arguing with me last week that her jetting was spot on. At 2900 feet I run a 42 or 45 pilot fuel screw out 2 to 3 turns and stock needle on the 4th clip and a 175 to 180 main. You might check to see if your "engine builder" changed back to keihin main jets and left the dyno jet needle in the carb. As far as the stage II cams having trouble idling this is not true it is in the carboration not the cam

[QuadJunkies]

Originally posted by Colby@C&DRacing
I hate to say it but I TOLD YOU SO . I remember some one arguing with me last week that her jetting was spot on. At 2900 feet I run a 42 or 45 pilot fuel screw out 2 to 3 turns and stock needle on the 4th clip and a 175 to 180 main. You might check to see if your "engine builder" changed back to keihin main jets and left the dyno jet needle in the carb. As far as the stage II cams having trouble idling this is not true it is in the carboration not the cam yes.......when I was talking to you about it then,it ran great!!! Just overheated alot and was WAY lean...So now after changing the pilot and jets, it runs worse than it ever has......it runs like crap......:( I think he already checked the needle but Ill ask Troy again...