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Jd red vs N3EJ needles.....

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I have an 05 YZ250 and just getting some final jetting sorted out. I wanted to know what is the difference (performance wise) between the N3EJ and the JD Red needle-both at #2 clip position?

I also posted this in the jetting forum, but this location gets more action..

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does the N3EJ needle come stock on an 06 yz250? If so then i have both and can go take some micrometer measurements for you.

I know JD brags about their custom triple taper needles but thats about it, it did add some nice mid range to my bike.

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does the N3EJ needle come stock on an 06 yz250? If so then i have both and can go take some micrometer measurements for you.

I know JD brags about their custom triple taper needles but thats about it, it did add some nice mid range to my bike.

Interesting. :)

Yes, N3EJ came stock in 06 followed by a fatter one in 07 N3EW.....

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hmm i have an N3EJ in my 99 is came with it in it on the 2nd clip position and it was running rich and fouling plugs all the time, so i moved it to the top clip and it made a world of difference.

funny thing is, i have a 2000 yz250 manual, on one page it states the N3EJ being the leanest needle you can purchase, of th enext page to it it states that its the richest needle, so i have no idea but the top position helped A LOT

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Please do Rusky.

OT: I wish he'd sell ONLY the needles. I dont need triplicate of every jet Keihin makes. :)

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Please do Rusky.

OT: I wish he'd sell ONLY the needles. I dont need triplicate of every jet Keihin makes. :)

I hear ya.. Only the good Lord knows how I came up with over 10, # 178 MJ's... :banghead: Its a mystery!! Ive only bought two of these bikes :banghead:

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Alright i played around with the micrometer for a little bit here are the results.

Both needles start at 2.75mm

The N3EJ needle starts to taper down sooner than the JD red needle (9.35mm vs 12.94mm from clip side***)

18.27mm (from the tip side***) of the needles:

N3EJ and JD red: are both around 2.20mm-2.23mm

Right before the needle point taper:

N3EJ: 1.82mm

JD red: 1.92mm

Let me know if you guys want any specific measurements aside from these or if you want to me clear something up.

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I hear ya.. Only the good Lord knows how I came up with over 10, # 178 MJ's... :banghead: Its a mystery!! Ive only bought two of these bikes :)

I hear a 178S MJ makes a good cigarette filter.....

OT: I wish he'd sell ONLY the needles. I dont need triplicate of every jet Keihin makes. :banghead:

If he did remove the Keihin jets I'm sure the price would remain constant. He's got to get his R&D paid either way.

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I hear ya.. Only the good Lord knows how I came up with over 10, # 178 MJ's... :banghead: Its a mystery!! Ive only bought two of these bikes :)

My 06 came with the 178 in the bike, and 2-178's in the bag:lol:

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nice work rusky-

so both needles are the same at lets say 0-1/4 throttle, then does that taper suggest lean or richer condtion in the middle? i want to go with the leaner of the two, assuming the same clip position at #2.

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The JD needle should be leaner since it would block more fuel from entering the carb body, fix me if im wrong though.

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I hear a 178S MJ makes a good cigarette filter.....

You must roll pinners then :banghead:

Thanks for the report Rusky :)

so... the red needle is leaner in the mid-throttle than the EJ. Any agree/disagree?

I'm after a needle that's richer at 3/8-1/2 throttle (only) than the EW. I'm trying to tune the bike for peak pump-fuel efficiency.

I'm ready for FI smokers!

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I agree it's leaner than the EJ, i'm curious about the blue needle since it is supposed to be richer, down low in the throttle range

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I'm after a needle that's richer at 3/8-1/2 throttle (only) than the EW. I'm trying to tune the bike for peak pump-fuel efficiency.

That's a 1/8 range of throttle - a tall order. Maybe the blue one for the blue bike then... :)

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The jd needle is right on the money..its almost identical to the other jd needle in the pack, but 1/2 clip difference.

Without getting technical, his triple tapers fill in the lean spots while leaning the rich spots. I compared the tow your talkign abotu back to back and never bothered with oem crap again.

If you want some fun, set your timing exactly, then drop the jd needle in.

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The jd needle is right on the money..its almost identical to the other jd needle in the pack, but 1/2 clip difference.

Without getting technical, his triple tapers fill in the lean spots while leaning the rich spots. I compared the tow your talkign abotu back to back and never bothered with oem crap again.

If you want some fun, set your timing exactly, then drop the jd needle in.

So the blue is a 1/2 clip position richer than the red, the other thing that is nice it appears that with his jetting it is not as sensitive to temperature changes(or is that just me)

Makes sense when i remember what the directions say LOL

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rc, do you remember what prompted you to utilize the blue needle? what was you ending point with the red? where you red clip#2?

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If you want some fun, set your timing exactly, then drop the jd needle in.

Please elaborate.

In the timing thread it looked like setting the timing was some what subjective to what you wanted from the bike.

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hollywood,

does the manual relfect where the timing should be or do it need the service guide? I would like to know if my 05 YZ250 almost has timing issues or not.

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Check the timing sticky up top, lots of great info:worthy: :)

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