any idea

[ron4938]

well i am workin on my buddys z400 its a 04 pretty much stock, well he bought it and he picked up a dg pipe from a local dealer, he got just the slip on and k@n filter with a prefilter. he also picked up a dyno jet kit i think stage one if it matters, well so we threw the pipe and filter on pulled the carb and put i think it was a 150 main and took the air screw 3 turns out. and it runs like crap, it ran good for a day or so and he took it out on a nice road to open it up see how it felt and it ran like crap he said it stopped pulling felt like it was boggin out. and on his way back to the woods it shut down on him, it will idle but any thing past 1/4 throttle it shuts off. i am gonna work on it tom any ideas?. i am gonna clean the carb and maybe put it back to stock see if it still messes up. but i was lookin at the main jet and i put it next too the stock and the stock was wayy bigger then the 150 could they have sent him the wrong jet kit?. any help would be great thanks..

[Grimzella]

3 turns out sounds like alot to me.. mine is 1 1/2 but i do have a 25 pilot jet. a 150 dynojet sounds smaller than a oem 150 main.. i run a 155. main might be to small there is a chart comparison here somewhere or just google it... what happens when the airbox lid is removed?

[cataway]

with the lid off atleast a 155 mj -162.5 25pj

[ron4938]

we did every thing the directions suggested us to do. we ran it the whole time with no lid, we put it back on and it ran like total crap. i am waitin on the jets to come in. i picked up a 25pilot and a 132 main and a 140 main. i guess i will find out how it runs after that.

[jonboy]

I agree with Cataway, when you open up the airways on the Z it is very responsive to the slightest mods so going down in main size isnt going to help. You should go to at least a 155 or higher. 25pj is about right but, you should only want to go about 2 to 2.5 turns out on the fuel screw though. When you get to 3 turns out you want to start going up in main jet size. The reason it is running the way it is is because it is starving for fuel. Be sure to do plug chops when your done to see where you are at then you can fine tune it with the fuel screw if your close. Anytime you make a bike breath better its going to have to have more fuel.

[John Noftsinger]

Did you get new needle in kit?I got slip on and jet kit without needle it ran ok but then i read on here about changing needle since then it runs awesome.Cathaway the man on jeetting if he cant tell you no one can by the way cathaway love the dyno results man.

[ron4938]

Originally posted by jonboy
I agree with Cataway, when you open up the airways on the Z it is very responsive to the slightest mods so going down in main size isnt going to help. You should go to at least a 155 or higher. 25pj is about right but, you should only want to go about 2 to 2.5 turns out on the fuel screw though. When you get to 3 turns out you want to start going up in main jet size. The reason it is running the way it is is because it is starving for fuel. Be sure to do plug chops when your done to see where you are at then you can fine tune it with the fuel screw if your close. Anytime you make a bike breath better its going to have to have more fuel.

thanks for the info and help bro. ok ill keep that in mind and ill up the main and the pilot. what i didn't get was it ran good when he just threw the silencer on with no jetting, then we upped the jets and it hasn't ran all that well since. i think they may have sent me the wrong jets cause they seem small for some reason. i order two small jets from jets r us see if they look the same and if it runs some what better. then if it helps then ill order up some bigger jets. yes the kit did come with a needle we try ed it at first and it would idle but would pop pretty bad when you try ed to ride it, we swapped it back for the stocker and it went away. if my jets come in tom ill work on it and maybe get a good vid. thanks for the help guys,

[twincat800]

You wasted your money on a 140 and smaller jet, you need more fuel than that i also like cataways suggestion. Start out with a 155main and see how it runs.. will be muchhh better (with the 25 pilot also)

[twincat800]

I personally dont know how much an aftermarket needle helps, but i ran the stock needle when i had my stock carb and that was with a slip on, k&n, and hot cams, ran good.

[ron4938]

Originally posted by twincat800
You wasted your money on a 140 and smaller jet, you need more fuel than that i also like cataways suggestion. Start out with a 155main and see how it runs.. will be muchhh better (with the 25 pilot also)

yeahhhh ik, i only order the mains to see how they matched up to the other jets i got with the kit. i ordered a 25pilot. if it still runs like **** then we will put it back to stock and just ride the damn thing lmao. and a 155 main with a airbox lid on?.

[ron4938]

well i got the jets, i pulled the carb out and pulled the slide out and the e clip was no where to be found. so thats why it wouldn't run hahah. so i put the 25pilot in it, and put the aftermarket needle in it on the 3rd clip,and i put the 140 main and it runs good but i think its too fat on top end. cause it pulls good on bottom end but it doesn't wanna rev out mid-top end. i didn't get to check the plug yet. i didnt think it would be that rich for almost sea level and 2turns out on the airscrew?.

[John Noftsinger]

You need 150+ main jet 140 too small!

[ron4938]

how are you so sure?. i am gonna try a 165 that i have this week end. prolly put the airscrew at 3turns out see how that gos. but i figured since it doesnt wanna rev out it would be to fat?. cause it doesnt sound lean or doesn't spit or pop on deceleration. ill mess wit it some more this week end. thanks for the help guys/

[Grimzella]

Originally posted by John Noftsinger
You need 150+ main jet 140 too small!

My thoughts exactly!

Your asking for help.. but yet, you question the responses?

if your main jet is to small, it will not be giving the engine enough gas, because once the needle is out of the main jet... the "size" of the main jet controls the fuel flow.. so if the main jet is to small.. you are starving your engine of fuel.. hence.. no power at top end!

Get a 155 Mikuni.

[T-Chad24]

those jets are super small, and anything thats bigger than that that gets in there could clog them up. That is what mine did one time. Try cleaning the carb, and the jets.

[John Noftsinger]

You need to start at 150 then 152,155,etc with after maket needle on 3rd clip ! 2 1/2-3 turns out .the dyno kit will tell you what evelavation you need to determine jet to use as well.If you got kit or maybe someone can copy dyno chart for him so he can see for himself !