AAAARGH!!! New needle not working as planned

Bought the new stock YZ needle for the WR. I am running 160 main 48 pj. Started at position 4 ran horrible. Turned the fuel screw all the way in, and idle went through the roof.ok, I figure I am too rich on the clip, so I lower the clip to 3 from the top. Same problem. I am using baseline jetting from local folks who have used these settings...any suggestions???HELLLLLP!!!!! :) P.S...I am at 30ft above sea level

As I have been saying all along on this forum the stock YZ needle is not always the right choice and some of the resident experts think you just slap in a YZ needle and away you go. The stock YZ needle is for a YZ timed and uncorked WR. If you dont have that you are to rich with the needle diameter. You need a leaner YZ needle. Can you list your mods so we all can give you a suggested needle to try.

Go back to the stock needle in the 4th position. 48 Pilot,160 Main, One half turn back on squirt screw. 2 turns on air srew. Start thinking about a 72 PAJ :)


Thanks for the info..I have the stock wr cam in it. I was told that the YZ needle would fix the o-1/4 flat spot in the throttle response. As far as the mods...airbox baffle removed, YZ throttle stop. FMF q series.gray ty fuel screw. I appreciate everyones patience and time with this issue..I am seeing that more isn't always better!


I think the bog can be fixed with the Accelerator pump adjustment. You may be putting in to much fuel and getting a flat spot off idle. Fix this first. Then determine if you can make the stock needle work. I liked the stock needle with the baffle insert in clip #4 or #5 if you are getting a lot of popping on decel from 1/4 to half throttle try raising your needle some more. The Q series pipe is designed to be quiet and flows slightly better than a stock pipe with the gytr insert. If you cant adjust it out I would try to start with a Yamaha OBEK-Q needle. This is a richer needle but about half way between the stock YZ needle from the WR needle. I use it at higher altitudes with my set up.

I am no expert, but, I think you are too rich on the pilot jet. If you turn the fuel screw all the way in and the bike does not stall, you are too rich on the pilot. I also tried running a 48 pilot and it was way too rich for my bike. Dropping down to the 42 fixed the problem. I am running a 42 pilot now with the EKP needle in the 4th position.

I have had good luck with my YZ needle. I have it in the 4th position. My WR has a stock pipe with the PMB pickle. I did ther usual free mods. I had better luck with a 158 main jet. Every bike seems to be a little different. Your FMF pipe will change the jetting as well.

I has been raining evey day for weeks so I've had plenty of time to play in the garage.


I ended up changing my Jetting on Sat for the Fool's Gold Enduro... I had to cork the Yosh with the smallest tech insert to pass sound and went to: 160MJ (down from 165), 48PJ (down from 50), YZF needle 4th Clip (down from 5th), 2.0 turns on the Ty Davis screw... When I took out the insert and rode around a bit, the bike ended up hitting better than the richer configuration!

i think you're all answering your own questions!

leaner is sharp as long as it isn't lean! and if it were it would definately let you know!

there is no way these bikes need a 50, 48, 45 or even a 42 PJ at any level!

40 is the max with a PAJ or PAS to suit, so come on lads. when i stopped here a year ago i left the jetting in safe hands i thought at 40PJ max, sure every week some body came along and said i got rid of a misifre with a 48 or the cough and splutter went with the 45.

however truth is stranger than fiction and thes bikes can give you lots of grief when they are partially rich. if you does them in fuel, blunt their edge and wash away there power YES YOU WILL GET RID OF YOUR TROUBLES_APPARENTLY!

but it's a cul-de-sac a dead end.

leaner jetting and it was better, now i wonder who took us there? mmmmmmmmmm!

indy speaks a great deal of sense when he says that it's too simplistic to just buy a YZ needle! i think hick must have started all that. i don't even know what a YZ needle is! seriously, why should i? after all they change the phuqing thing every year :)

what would add to indy's comments though is that you have to turn everything down, especially around tickover, first gear stuff.

i'm talking PJ, PAS, APJ, lower the main (which effectively is like lowering the needle at lower revs) everything on these goes down and down. if the bike didn't run better everytime it would get depressing!


Thanks for the wise post Taffy. I have yet to work down to the 38PJ but I think I am going to try it and see what the results are like. Good to see you still hanging around this forum. Hey Taffy, What bike are you riding these days? :)


if you're running 42PJ with 2 turns out on the PS and yoiu swear that after doing snap wheelie tests that that was the best set up:????? well i think you have got to either be

running a 100PAJ

have a fat needle like a Q or an R

or the needle on clip 1 or at best 2.

when i used to stand up on mine and squirt around the back of trees, or oh! sheet here's a bottomless pit coming up, man was i glad i could haul on the bars, pull the throttle and make it.

another classic was the 1 in 4 hill in slim on tickover with a stealy 10oz steak fitted. never stalled and often popped a little one over the top.

am i the only rider that lives in this environment?

as my signature says;

i'm riding a husey FE400e and i love it!


The stock YZ needle sucks....There are many better needles out there. I tried many while the Taffster was experimenting a couple of years ago and found that for explosive power the OBEKN needle was without a doubt the most explosive of them all.... Even Taffy agreed after JD recommendeded it. To this day it's the best race needle I've ever used.

Taffy and I agree to disagree on many things, including the use of a 42/75 for summer or the 45/100 for winter. It worked for me for two years of hard racing. I do however have to admit that it was a tad rich (Which I like as not to blow engines or create artificial overheating conditions. I did try Taffy's 38/65 150/160 combination and found it to be very good for me from sea level to about 2800 ft, but in my bikes a little lean over 3000ft and just on the edge of pinging. I also found that running my starter jet all the way down to 50 from the stock 65, gave the bike that extra kick it needs to start cold without loading the carb to the point of rolling black smoke out the exhaust can when pulling the throttle with the choke pulled.

JD's jetting guide is a must for troubleshooting many of the various problems at different altitudes and temp ranges. (You do however have to be a HS Grad with an interest in rocket science and physics to really grab ahold of what JD has done with the data.) Still it's a great document and worth the money thru the TT store. and actually is now more important since it seems that the Original Jetting Q's thread seems to have disappeared into the great abyss that originally formed the basis of JD's document and the baseline theory that was established concerning jetting of the Blue Beast between Taffy and JD, with input by many others as well. (Glad I printed it before all the server changes).

anyway my 2 cents....

Good to see you out here occaisionally Taffster....

Bonzai :)


The jetting qs thread lives on..ya gotta type Jetting qs without the '

Helped me out tremendously.Now to get the parts and start testing!


Ok..I read ALL the posts in jetting q's and have come up with this based on altitude and a combination of riders/experts opinions and funny pretty much mirrors Taffy's suprise there. So I just placed my Sudco order for the following parts:

EMM Needle

160 MAJ

35&40 PJ

Sudco slow Air Screw

150 MJ

60 ST

My only q's at this point is since this has been used succesfully for most 400 & 426's that it should be pretty close for the 450 with some minor tweaking. The other q' is I am running the stock wr cam. Soooo the adventure begins. Once again thanks to those of you who have supplied the answers to the puzzle so far, and Taff..if ya have any comments about the q's I have, they would be greatly appreciated!

Skol bro's :)


we've never had a crossed word before and i don't want to start now but i won't have anyone take what i did away from me.

the EKP was JD's needle, nothing else, that was the one. as you can see in jetting Qs when i was running 200MAJ my jetting took me well away from his figures and it came back again with the 160MAJ. he could never forseen that in his crystal ball, i forced him to play his cards in the open, to tell us all what he knew and he didn't like it because he was giving away what he knew in order to keep up.

he was busy filing his own needles that's what. there's nothing that you can't do by purchasing the right parts from keihin.

of course what you really need is to create a demand that only you can meet. all jets are incremented. the one mythical commidity is the NEEDLE what better to create a market by slapping coloured codes on needles and go to a new level of bull!!

whose intersts is it in to stop him, TT don't know any better do they?

but my pilot numbers were way way lower. i mean his 45 to my 40 and counting 38 down 35 to the bottom! they always were, and always will be lower, i was told for sure it had to be a P and it was an M straight for sea level. i invented the Taff Mod in twenty minutes having set the bike up over a year without a drop coming from the APJ which i was the only one advocating that the APJ is a worthless piece of junk. now we have so little that the APJ barely functions because the pump loss is greater than the fuel required.

i don't know much about american sport but i'll try this one coz i l-u-r-v the blues brothers; it's like moving all the stands at wrigley fields around one place and saying yep! but the pitchers centre spot hasn't moved. i guess if you say EKP you're never going tobe far away.

whilst my gearbox was broke andy and in aus and JD swore that a 230MAJ was it. nobody did any testing. when i put the bike back on the track i spent 3 hours fastidiously checking that we had all been duped and had gone in the wrong direction. the change of MAJ changed the MJ which dropped the needle which allowed a wider straight which allowed a larger PJ. (remeber that i went down to 35 and then back up to 38 then down to 35 not because i'd got it wrong but because i was putting in the graft and finding out the relationship of everything)everything knocked on.

i was the one who bought the PAS here, i was the one who put the ratios up that are used today. i always put the theories up and put my gob on the line everytime.

i'm the one who isn't trying to coin it, i'm the one who still comes back to where it all began to offer a bit of advice.

my views were so far out that i could have screamed, but i would chip away, chip away, chip away until in the end an american in switzerland had the big bollocks to try my settings, if he hadn't i think i'd still be out there talking to myself now.

through just one, then two, then three people started to take my advice and try things and don't forget that at that time JD and clark mason could do no wrong. what a battle. the mad welshman versus the home boys, maybe you were unaware of the battle i faced, sure i've opened my gob, and had it filled a few times but on this one i handled it like a pro. any kind of frustrated angst thrown at anybody would have seen my views quashed as as mad as me.

if i disagreed with patrick burns write up, i said it, and then in his next edition he would adjust things and 'he' was right!

JD and i had chats about the needle straight versus taper start, i sorted it, i always played my cards in public. i proved his theorries wrong several times and i doubt if any true testing has been done on since.

on the basis that you need less fuel to air at altitude i'm amazed to hear that PJ # go up and that if i run 150MJ at sea level that there aren't any yanks on 140+ at altitude.

yami, JD advocated the EKP for everything, everytime he said you gotta go that way i proved him wrong and went the other! he advocated the 'F' taper; don't see it out there now though do ya!

i continue to nail problems first time up.

sorry, but if he said EKN he said a lot of other things as well. pretty much anything you wanted to hear in fact, for me i chased a cul-de-sac in the 48PJ etc but i think i only went the wrong way once in the next 150 tests.

i've just set my husey up in about 18 test rides, it just so easy now.

anyway good luck, i agree that JD's chart is excellent and anyone getting serious should get one. shame i lost mine last year in a melt down but there you are.

i'm glad you've profited from my work old fella, i would have done the same in your shoes.


touche' Mr taffster,

I stumbled onto tt when I first bought my 2000 WR 400 and followed jetting Q's pretty much as it happened.

At first I was reluctant to dive into this big fourstrokes fandangled carb, but I worked up the confidence and asked all the usual jetting questions. Despite the "go richer" advice of others and a short stint with the ELN needle, 42 pilot and 165 main,I eventually took your advice over theirs and went leaner in jet size and used the EMM needle as you suggested I do.

Every person that has had a ride on my 'taffy' jetted 400, most of them 426 owners, or local bike shop mechanics/tuning gurus, have come away totally amazed at the feel of the bike. I can start the bl#*dy thing with my hand, it will lug up hills at ridiculously low revs without stalling, it will pull top gear wheelies at 100 kilometers an hour on the highway and it will hit the rev limiter in top with 14/48 gearing at 160 kmh(with a panaram fitted).

I have 8500 kilometers on the clock and not one single fouled plug or engine problem to speak of.

Two words that define the whole feel of the bike stick in my mind "seamless metering". I doubt I would have enjoyed the bike anywhere near as much without your patience and valuable advice.

In my blue world YOU are the man taffy!!!!

Its good to see you back in the forum again.

cheers from australia,


Geez....a little touchy there big fella.... I do not believe that anyone has taken anything that you accomplished away from you. What you accomplished in a relitiveky short period of time was and is to be commended. However JD's contributions were just as important and ground breaking as your own. Granted, you went very lean before anyone else....But I seem to remember many many conversations between you and JD that were in other threads besides the Q's thread where many of the theory's were discussed and mutually brought to the TT community through trial and error.....(and there were many) As you are aware (when sober anyway) I have much respect for you and your contributions, I have the same for JD as well. The point I'm trying to make here is that you were BOTH pioneers here, and your hard work and diligence paid off big time for many more than just yourselves. To indicate that your work was more important than JD's is just wrong in this instance. I can remember just as many folks that JD satisfied as I can that you did. Hell I've run both of your recommended settings and have been satisfied with them all at certain times since 91. Personally I have helped many a rider out at the race track with the knowledge that I obtained from the both of you, and for that I am very grateful. An Yes JD did initially recommend the EKN with the WB E-series, and it works fantastic. As I recall I also discussed it with you before I went in that direction and you agreed.

So don't blow a gasket there big "old" fella....Nobody is trying to take anything away from you.

Bonzai :)

JD claimed that he came up with the 'E' series first, before yamaha did on the '99 model. however i went back to the very first thread that he recommended the 'EKP', do you remember the threads that were just blocks that started on the left and the index's gradually moved in field? well the date he put in his first test was a full three months after the '99 model came out. i've kept that under my hat for three years. well yami if an argument serves no purpose why have it? agreed? so i left it there.

his PJ's never changed, he went the wrong way with the MAJ completely, said you needed the APJ or it didn't operate. he only ever knew of two PAJ's the #75 and the #100-that was it! two!

all he repeatedly kept saying was EKP and a 45 PJ so stop kidding yourself yami. if i'd have said anything bad about him at the time they would have sent a boat over and had me publicly flogged.

what he was first to (and in no way does this make him a pioneer of so let's seperate the two) was the charts, the graphs and what they stood for, over here we never had anything like it. if you have the charts you have the power.

when someone quoted EKP and EMM and DRQ to you, up 1, down 1 at the beginning did you understand it? nope! and neither did anyone else.

suddenly, at last we all got to know how he knew. that's what made him king pin. he had been at it 6 months longer than anyone else and was pretty much one step ahead all the time.

but as far as pioneering, first there, teaching, first up with the formulas like 'the MJ controls the needle' i think you've got to say that it didn't come from him.

but when faith is ingrained then there is little more to do or say.

i don't know what's going on over the orange side but i did catch a 5-minute glimse and i tell you this, there is nothing that can't be done with the standard needles and jets on these bikes. there isn't a need, one has been created in riders minds.

if our american brothers have a weakness it is the desire to believe people too easily. maybe you don't spot it among yourselves but when you come over the pond people slap hands to heads and after a while and have to say "that's us!".

still if you go orange your a blurry iriot anyway!


JD claimed that he came up with the 'E' series first, before yamaha did on the '99 model.


I was under the impression that Yamaha didn't use an E needle until the 2000. I'm pretty sure the YZ 400 always had the DVR, I do know the '00 426 had an EKQ.

then maybe it should read "in late 99 after the '00's had come out" WGAS.


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