Almost got it dialed in!

[rooster300ex]

I finally got my quad where it runs really good except at 1/8 throttle it surges & cuts out alil bit but if i give it anymore throttle it clears up and runs fine. I'm pretty sure i can fix this with the fuel screw, from what i'm tellin ya do i need to richen or lean it up a bit. Right now its 3 turns out, like the dynojet kit said. I've heard that certain cams can make your pilot circuit hard to fine tune. Is this ture?

[Sjorge450R]

Originally posted by rooster300ex
I finally got my quad where it runs really good except at 1/8 throttle it surges & cuts out alil bit but if i give it anymore throttle it clears up and runs fine. I'm pretty sure i can fix this with the fuel screw, from what i'm tellin ya do i need to richen or lean it up a bit. Right now its 3 turns out, like the dynojet kit said. I've heard that certain cams can make your pilot circuit hard to fine tune. Is this ture?

I run a dyno jet in my 300ex as well. I have the needle set were they say for under 2000ft and my screw is about 2.25-2.5 turns out. Bring it in a little bit to cut off some air and add more fuel. Or try messing with the needle. Bring clip up on the needle and try that.

[GPracer2500]

Turning a fuel screw in is leaner, not richer.

[Sjorge450R]

Originally posted by GPracer2500
Turning a fuel screw in is leaner, not richer.


Yeah I dont know why I said what I said.....

[rooster300ex]

So yall think i need to lean it out alil by turning the fuel screw in about a half turn?

[GPracer2500]

Is it popping on deceleration? Is the pilot jet stock?

Do THIS (http://www.exriders.com/vbb/showthread.php?s=&threadid=229923)

[rooster300ex]

I'll do that thing you said if i can't fix it by turning it alil the way it needs to go, and yes stock 38pilot, and its not decel. its more of a popping,surging cut out. and when i take off at about 1/8 to almost a 1/4 throttle it will cut out and jerk alil until i give it alil more gas.

[krt400ex]

Originally posted by rooster300ex
I'll do that thing you said if i can't fix it by turning it alil the way it needs to go, and yes stock 38pilot, and its not decel. its more of a popping,surging cut out. and when i take off at about 1/8 to almost a 1/4 throttle it will cut out and jerk alil until i give it alil more gas.


ur pilot is prolly to small.

[rooster300ex]

Originally posted by krt400ex
ur pilot is prolly to small.


a 400ex has a stock 38pilot jet. I think i've seen when searching the forums that a 300ex needs alot of intake & engine mods for a bigger pilot jet.

when i pulled the plug i could see black,and on one side of the plug there was a dark brown spot. to me that is still running alil rich. i had the fuel screw 3 turns out, i look the carb off turned the fuel screw just about 2.5 turns out, and put in the dj120 jeti i've went from the 128,124 now the 120. Ill let ya know how it runs, i left the needle on groove 4.

[krt400ex]

Originally posted by rooster300ex
a 400ex has a stock 38pilot jet. I think i've seen when searching the forums that a 300ex needs alot of intake & engine mods for a bigger pilot jet.

when i pulled the plug i could see black,and on one side of the plug there was a dark brown spot. to me that is still running alil rich. i had the fuel screw 3 turns out, i look the carb off turned the fuel screw just about 2.5 turns out, and put in the dj120 jeti i've went from the 128,124 now the 120. Ill let ya know how it runs, i left the needle on groove 4.


u got alot of mods though. and where did u ever hear that. go in the direction that the quads symptoms are pointing, not what u think it needs according to what u heard. try turning the air screw out and if that doesn't work then get a larger pilot. also, the dj jets are much larger than the keihin jets. with the mods u have i would run a keihin 135. the dj 128 sounds a little large. the 124 should work though. it also depends alot on ur elevation. i'm saying this based on the fact that i'm at around 3000 ft

[rooster300ex]

Originally posted by krt400ex
u got alot of mods though. and where did u ever hear that. go in the direction that the quads symptoms are pointing, not what u think it needs according to what u heard. try turning the air screw out and if that doesn't work then get a larger pilot. also, the dj jets are much larger than the keihin jets. with the mods u have i would run a keihin 135. the dj 128 sounds a little large. the 124 should work though. it also depends alot on ur elevation. i'm saying this based on the fact that i'm at around 3000 ft


Well i'm at about 500-800ft in southern oklahoma. when i turned the fuel screw from 3 turns out to 2.5 i don't think it helped. i also went from the 124dj to the 120 and i think a few times when i was in fourth wfo i heard it kinna cut out for a second. i'm gonna put the 124 back in, and turn the fuel screw 3.5 turns out. what about he needle. i think it might surge & hunt alil at like almost half throttle. i'll get er dialed in someway.

[Sjorge450R]

try the 128 Dynojet. And set the needle up for the way the directions say.

[rooster300ex]

Originally posted by Sjorge300EX
try the 128 Dynojet. And set the needle up for the way the directions say.


I had the 128 in when i first jetted it. It seems to run the best with the 124. the needle is on groove 4, 2.5 turns on the screw,120dj.

the throttle is crisp when i first start it, but when it gets hot its not. it surges & hunts when i'm just crusin along. it pretty much loses throttle response,and surges at 1/4 to almost 3/8 throttle. i'm tryin to get it to have a crisp throttle when i start it and when i'm giving her hell. i'm going by the plug, and its more of a blackish color then the cardboard color it needs to be. also i have my choke removed.

[Sjorge450R]

Originally posted by rooster300ex
I had the 128 in when i first jetted it. It seems to run the best with the 124. the needle is on groove 4, 2.5 turns on the screw,120dj.

the throttle is crisp when i first start it, but when it gets hot its not. it surges & hunts when i'm just crusin along. it pretty much loses throttle response,and surges at 1/4 to almost 3/8 throttle. i'm tryin to get it to have a crisp throttle when i start it and when i'm giving her hell. i'm going by the plug, and its more of a blackish color then the cardboard color it needs to be. also i have my choke removed.

um, explain surge??? Is it popping, cutting out, back firing?

[rooster300ex]

Originally posted by Sjorge300EX
um, explain surge??? Is it popping, cutting out, back firing?


It's cutting out. It doesn't pop or backfire at all.

[Sjorge450R]

Originally posted by rooster300ex
It's cutting out. It doesn't pop or backfire at all.


cutting out like its running out of gas, Or cutting out from too much gas. I think you should put the 128 in and put the needle on the 3rd postion.

try that.

[rooster300ex]

what about the fuel screw. its a stock 38 and i have it 2.5 turns out.

[Sjorge450R]

Originally posted by rooster300ex
what about the fuel screw. its a stock 38 and i have it 2.5 turns out.

leave it like that.

[krt400ex]

Originally posted by Sjorge300EX
cutting out like its running out of gas, Or cutting out from too much gas. I think you should put the 128 in and put the needle on the 3rd postion.

try that.
\

or u could try something in between. does dj make a 126? maybe try that

[Sjorge450R]

Originally posted by krt400ex
\

or u could try something in between. does dj make a 126? maybe try that

yeah but the 126 doesnt come in the kit. try the 128 that is what I am running and my bike is simular to yours.

[rooster300ex]

Ok i'll try the 128 maybe, but it seems to run better with the 124. and the main jet isn't my problem really. i'm tryin to get my throttle crisp, and try to get it to stop cutting out when i'm barely on the throttle.

oh yea and you live in philly & i live in oklahoma. big difference there. you gotta factor that in too.

[Sjorge450R]

im at like 49 above sea level, youare around 500. I race at over 2000. So your setup is going to be the same. Its prob running good WFO with the 124 cause your leaning it out. Try richening the needle up then. Im not sure which way to go on the needle, but I think that it is the higher up the clip the leaner.

[rooster300ex]

Thanks for your help, but your tellen me to richen it up, but the plug is showing its running rich. i didn't do a plug chop or anything, its just been in there for a lil while and its more black then anything.

ok right now i have 2.5 turns on the fuel screw with stock pilot jet,needle on groove 4,120dj.

you want me to keep the fuel screw at 2.5,put the needle on the 3rd groove for less fuel, and put the 128dj in.

correct me if i'm wrong because i'm gonna try it. if your quad runs good and you race it and this is your setup i'll try it.


what is your whole intake setup. filter to jets to etc.

[rooster300ex]

bump