Jetting....

[WhY_ZeE]

Ok hm i have some jetting problem..hope you can help me out..

400ex 01, 165main, 3turn½ out pilot position, #3 needle clip.
Air box open,K&N filter + pre filter.

My problem is when im like 3/8 throttle, he's not running well. i feel it pretty more on the wheely, it kinda bug i have to give 2x more gas to feel the power..or when i hold the throttle at 3/8 he doesnt run well...i don't even know if he is too rich or poor..but low and high rpm im fine..( sorry if i have problem explaining, i'm not english..)
I will try to play with my needle jet tonight...
Do you know whats the prob ?? MAYBE...my float but i don't think so..thank for helping..

[WhY_ZeE]

any1 ?? :ermm:

[Guy400]

Turn the air screw in, in 1/2 turn increments, and see if it gets any better. On my set-up 3-1/2 turns was too much and the quad would bog a little off idle up through about 1/2 throttle. I went in a 1/2 turn to 3 turns out total and now it runs like a champ.

[AtvMxRider]

Guy's an expert on this jetting stuff now....;)

[Guy400]

Originally posted by AtvMxRider
Guy's an expert on this jetting stuff now....;) And I've got the bloody knuckles and half gallon of gas spilled on the floor to prove it:D

[WhY_ZeE]

Originally posted by Guy400
Turn the air screw in, in 1/2 turn increments, and see if it gets any better. On my set-up 3-1/2 turns was too much and the quad would bog a little off idle up through about 1/2 throttle. I went in a 1/2 turn to 3 turns out total and now it runs like a champ.

Yea i tried it already..Didn't feel a difference..

[WhY_ZeE]

by the way i just took off my plug, she was all carbonized...

[WhY_ZeE]

My idle is fine though, its only about 3/8,4/8 throttle...
I guess i will try 2 turn and half out pilot.. what do you think ?

[UglyMotha™]

try goin down some with the main jet that sounds masive for your application are you still running the stock exhaust you didn't mention haveing one but with those mods you really shouldn't be any higher than like 155 i think i'm running a 165 with the mods i have and it still seems a little rich

[WhY_ZeE]

Originally posted by UglyMotha
try goin down some with the main jet that sounds masive for your application are you still running the stock exhaust you didn't mention haveing one but with those mods you really shouldn't be any higher than like 155 i think i'm running a 165 with the mods i have and it still seems a little rich

Yes stock exhaust..but main is more 3/4 to full throttle, my problem is not there...maybe its rich anyway..In the installation sheet that came with the K&N kit, they suggested a 165 main...
i guess i'll try a 155-160 then..

[UglyMotha™]

never mind your talking about dyno jets there #'s run big so leave it at 165

[UglyMotha™]

did screw you air/fuel screw out 3 1/2 turns from where it was already at or did you screw it in until it stops then screw it out 3 1/2 turns

[WhY_ZeE]

Originally posted by UglyMotha
did screw you air/fuel screw out 3 1/2 turns from where it was already at or did you screw it in until it stops then screw it out 3 1/2 turns

Well i screw it clocksize until it stop then 3 turn and half out..
But right now im 3 turn out.. Just put a new plug and tried it, my plug was starting getting black..So ok i'll leave the 165 main..

[WhY_ZeE]

The problem is not my main, 165 and my 3/4 to full throttle is fine anyway. My pilot screw, i put it 3 turn out, my jet needle 3rd position....... can som1 explain me why my quad isn't doing fine at 3/8 throttle...?

[WhY_ZeE]

Help me ! ! :(

[Guy400]

For *****s and giggles drop your main down one size. The needle jet rides inside the main jet a majority of the time (unless you're at wide open throttle). As a result, if you've got too big of a main jet in you can conceivably be causing a rich condition at mid throttle. I don't know what the next size down is in your kit but try it. I believe my K&N jet kit came with a 155 in it as well. I'm running a 165 DynoJet (what K&N uses) on my quad and that's with a filter, no lid and a pipe. If you simply added a filter and removed the airbox lid than your jetting changes should be minimal. I just looked at my K&N kit and it comes with a DJ155 and a DJ146 main jet. Leave the air screw at 3 turns out and leave your needle jet alone. Drop down to the DJ155 and if there's no noticeable difference go down to the DJ146.

[toby400ex]

Heres somewhere i might be able to find my prob, some people have said i might need to replace my needle valve. I have the k&n filter, outerwear, fmf slip on, needle on the 3rd groove, pilot 3 turns out and the main is a dj146, with lid on. It runs amazingly well, starts up like a wonder. But the plug is black as a mother. Some say it might be the needle valve, because it might possibly need replaced because the seal is worn, the rubber part looks fine, it is smooth and round and what not, if it was bad it would cause the bowl to flood a bit. THis might also cause the carb to loose alot of gas out the tubes, which mine does, it squirts all over that place when i just shake it by the bars. Please please please someone help me out. I want a pretty spark plug and peice of mind. By the way, my floats are perfect:confused:

[toby400ex]

bumparoo

[WhY_ZeE]

damn my main is stuck in his adapter (dyno jets..) :o
any tips ? :grr

[Guy400]

Originally posted by WhY_ZeE
damn my main is stuck in his adapter (dyno jets..) :o
any tips ? :grr Don't over tighten when initially installing them:D

[WhY_ZeE]

:scary:
I didn't...
i just dont know how to unscrew it... any tips ????

[WhY_ZeE]

Originally posted by WhY_ZeE
:scary:
I didn't...


Yes i did :o

[toby400ex]

Originally posted by toby400ex
Heres somewhere i might be able to find my prob, some people have said i might need to replace my needle valve. I have the k&n filter, outerwear, fmf slip on, needle on the 3rd groove, pilot 3 turns out and the main is a dj146, with lid on. It runs amazingly well, starts up like a wonder. But the plug is black as a mother. Some say it might be the needle valve, because it might possibly need replaced because the seal is worn, the rubber part looks fine, it is smooth and round and what not, if it was bad it would cause the bowl to flood a bit. THis might also cause the carb to loose alot of gas out the tubes, which mine does, it squirts all over that place when i just shake it by the bars. Please please please someone help me out. I want a pretty spark plug and peice of mind. By the way, my floats are perfect:confused:
Anyone have some advice for me?:(

[bklyn400ex]

i had a 155 main, and the plug was coming out black, i tried a 150, the plug was white, should i raise the needle clip up 1 notch, it was in the stock setting, or should i mess with the screw. i have simple mods, exhaust, KN filter, holes in airbox
thanx

[WhY_ZeE]

Originally posted by Guy400
For *****s and giggles drop your main down one size. The needle jet rides inside the main jet a majority of the time (unless you're at wide open throttle). As a result, if you've got too big of a main jet in you can conceivably be causing a rich condition at mid throttle. I don't know what the next size down is in your kit but try it. I believe my K&N jet kit came with a 155 in it as well. I'm running a 165 DynoJet (what K&N uses) on my quad and that's with a filter, no lid and a pipe. If you simply added a filter and removed the airbox lid than your jetting changes should be minimal. I just looked at my K&N kit and it comes with a DJ155 and a DJ146 main jet. Leave the air screw at 3 turns out and leave your needle jet alone. Drop down to the DJ155 and if there's no noticeable difference go down to the DJ146.

I tried a 155 main and it runs perfectly !! thank a lot

[toby400ex]

Originally posted by toby400ex
Heres somewhere i might be able to find my prob, some people have said i might need to replace my needle valve. I have the k&n filter, outerwear, fmf slip on, needle on the 3rd groove, pilot 3 turns out and the main is a dj146, with lid on. It runs amazingly well, starts up like a wonder. But the plug is black as a mother. Some say it might be the needle valve, because it might possibly need replaced because the seal is worn, the rubber part looks fine, it is smooth and round and what not, if it was bad it would cause the bowl to flood a bit. THis might also cause the carb to loose alot of gas out the tubes, which mine does, it squirts all over that place when i just shake it by the bars. Please please please someone help me out. I want a pretty spark plug and peice of mind. By the way, my floats are perfect:confused:
Shizphucknit, can anyone around here tell me if i really need to by a new needle valve:confused: :(