Needles?

Could anyone give me an idea on how the #s on needles work? like how a n3cj is different than a n3ew, n3ej, ect ?

it has to do with richer or leaner needle's. they move in half clip postion's

OOOO so if the n3cj was a leaner needle that the n3ew the bottem 3 positions on the n3cj would be the same a the n3ew top 3 but the top postion on the c3cj would be half clip leaner than the n3cj?

j has a thinner root diameter than the w needle, quite a bit richer regardless of clip position. The other difference is where the taper starts, that can be effected by clip position.

so the w is richer than the j ?

j is richer through about 3/8 throttle, then they'd be close to the same depending on the clip position.

ok thanks highmaker. the reason i am looking into this is that I have a n3cj im my bike now with the clip in the top position. I posted probly 4 different threads trying to find all the jetting specs for my yz and was being told to have the clip in the top postion but the people that were telling me this did not know what kind of neelde I had and I did not know that the needle made a difference so I am a little worried on running too lean, and after my brother locked up the piston on my uncles atv this weekend which make me more nervous.

I have 168 main, 45 pilot, n3cj needle in top postition, air screw 1 turn out, 50-60 degrees at 5000-6000 feet

Look up your specs here on this chart:

YZ250VJetting.jpg

ok thanks highmaker. the reason i am looking into this is that I have a n3cj im my bike now with the clip in the top position. I posted probly 4 different threads trying to find all the jetting specs for my yz and was being told to have the clip in the top postion but the people that were telling me this did not know what kind of neelde I had and I did not know that the needle made a difference so I am a little worried on running too lean, and after my brother locked up the piston on my uncles atv this weekend which make me more nervous.

I have 168 main, 45 pilot, n3cj needle in top postition, air screw 1 turn out, 50-60 degrees at 5000-6000 feet

scspencer,

Only the last letter follows a logical sequence for interpreting needle codes with the 4 letter Nxxx codes.

The last letter is the needle straight diameter, which affects 0-1/4 throttle. The higher the letter, the leaner your 0-1/4 throttle will be.

From rich to lean at 0-1/4 throttle - N3EG, N3EH, N3EW, N3EJ, N3EK

The N3Cx needles are 1/2 clip position leaner than N3Ex needles, so the progression is the same. The clip position is mostly affecting 1/4 to 2/3 throttle.

From rich to lean at 0-1/4 throttle - N3CG, N3CH, N3CW, N3CJ, N3CK

Considering the clip positions are only 1/2 step apart--

N3CJ #3 is equal to N3EJ #2.5 ( 3rd clip position shimmed up by ~1/2mm)

N3CJ #2 is equal to N3EJ #1.5

N3CJ #1 is equal to N3EJ #0.5

I hope this helps.

James

does honda, ktm, kawai ect use the same needles? The reason im asking is that i called all the yamaha dealerships the the area and none of them had needles and they said it would be a week before it came if i ordered one. I was planning on riding this sunday so a week does not work. Can i call the honda, kawai, suzuki and ask for the same needle ?

An FCR needle is a FCR needle. There are different lengths for different bore carbs, however. Take a read of the sudco catalog. It lists 99% of them. Some bike manufacturers use needles not listed in the chart but the needle simply 'fills in the blank spot' on the chart. Also, you can Google a needle number to see what bike companies list it as a replacement part.

Thanks william, still not having much luck finding a needle. looks like i mite be sitting at home this weekend

what nnedle are you looking for?

n3cj.

ok thanks highmaker. the reason i am looking into this is that I have a n3cj im my bike now with the clip in the top position. I posted probly 4 different threads trying to find all the jetting specs for my yz and was being told to have the clip in the top postion but the people that were telling me this did not know what kind of neelde I had and I did not know that the needle made a difference so I am a little worried on running too lean, and after my brother locked up the piston on my uncles atv this weekend which make me more nervous.

I have 168 main, 45 pilot, n3cj needle in top postition, air screw 1 turn out, 50-60 degrees at 5000-6000 feet

scspencer, I don't know what year YZ you have but the stock needle for many years was the N3EJ, I think it was 07' when they changed to the N3EW. The stock clip position for both needles is clip #2. If your worried about being to lean (no indication of actually being lean?)with your current N3CJ in clip 1, then I suggest you put it on clip 2, go ride and have fun. A 1/2 clip position leaner than stock shouldn't be to lean for your elevation at 60*. As JD pointed out N3CJ is 1/2 clip position leaner than N3EJ so your N3CJ in clip 2 will run the same as the N3EJ in clip 1.5. As far as needles go I have to disagree with William1, instead I feel this is where the magic is, must be the case as there are so many different versions available (single, double and triple tapers, different taper angles, different taper starting points, and different straight diameters), plus manufacturers continue to change them. I suspect there looking for the magic too! Just for the record you have a PWK not an FCR, and W is slightly richer than J from closed to @ 3/8throttle. :thumbsup:

ok thank you my yz is a 2002

shrubitup, where can i find a jetting chart like that for my 02' yz250f ?

shrubitup, where can i find a jetting chart like that for my 02' yz250f ?

PM sent to protect the privacy of the innocent. Not sure if he has the 250F stuff but you can try.

okay thanks .

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