N2ZK, N84K needles

[aj_mariner]

Ordered the needles above to give them a go. The N84K needle is listed as EU-Racing so figured why not. I know the NECJ has a large following. Anyone else try these out?

[dirtbird]

IIRC, the N84 is the homologation needle which comes together with a slide travel limiter and a seriously smaller main jet & air jet.
All those mated with a 125-size exhaust chamber with a catalytic converter and fresh air injection (via reed valves).
Rated @ 7KW.

Cancel it...

And N2ZK (writing this from memory so somebody please confirm) is 1 step leaner than N2ZJ.
So unless you're on the South hemisphere, be careful !!

[aj_mariner]

Currently using the N2ZJ. My understanding is that the N2ZK is smaller diameter. Trying to get rid of the slight lean condition from 1/8 to 1/4 throttle.

[KB112]

Currently using the N2ZJ. My understanding is that the N2ZK is smaller diameter. Trying to get rid of the slight lean condition from 1/8 to 1/4 throttle.

The K would indicate it is a leaner (larger diameter straight section) needle. The n2z_ needles are rich around 1/8th throttle. The NEC_ needles will clean this up.

[aj_mariner]

Well that's just great. The dealer told me that the K was richer than the J. Guess we'll find out when they come.

[aj_mariner]

Got the needles in today. Here are the measurements. Looks like we were both wrong...K is a distance change. Hope this helps.

IMG_0410.jpg (66.92 KiB) Viewed 14086 times

Apologies if the picture is upside down. It shows right side up on the phone, but flips itself when uploaded to the site and viewed from my computer.

[tiojose]

I dont see substantial difference in size.

On me EXC200 i got a JD kit.
Compared the JD size like you did, giving singnificant difference.
I remember the JD was much thicker on the taper think 0,1.
The main jet was 10 bigger
I took it being the EXC200 wasting fuel, what help zo get 2kms more out of a liter.
Also downsized the stationary jet, incidental sputter went with that.

[KB112]

Got the needles in today. Here are the measurements. Looks like we were both wrong...K is a distance change. Hope this helps.

IMG_0410.jpg

Apologies if the picture is upside down. It shows right side up on the phone, but flips itself when uploaded to the site and viewed from my computer.

The straight section diameter (right below where the clip goes) should be larger on the k compared to J. It is a very fine measurement. I will trust the manufacturers accuracy over your measurements. It is well known that the end letter on that series of needle represents the straight section diameter, which changes the air fuel ratio up to around 1/8th throttle. The N8RK should be the same needle only slightly longer (1/2 clip).

[aj_mariner]

The straight section diameter (right below where the clip goes) should be larger on the k compared to J. It is a very fine measurement. I will trust the manufacturers accuracy over your measurements. It is well known that the end letter on that series of needle represents the straight section diameter, which changes the air fuel ratio up to around 1/8th throttle. The N8RK should be the same needle only slightly longer (1/2 clip).

I agree completely. Will use the certified Starrett from work and update.

[aj_mariner]

Remeasured with micrometer. N2ZJ diameter is 0.1082” or 2.748mm, N2ZK is 0.1088” or 2.763mm.