Jump to content
Sign in to follow this  

Finally made a needle adjustment on the 285.. WOW!!

Recommended Posts

I had experimented with richer jetting on my needle, cause the 285 seemed to require a richer main.. So I never tried to go leaner until yesterday.. Needless to say, Im pissed at myself for not trying that sooner!! :) The bike went from amazing to AMAZING with a 5 minute job.. Two downsides though.. First, it may be to violent for the trails now and may need a FWW or taller gearing.. And I dont like running my bike in the leanest needle position and would like to get the next leaner needle.. It has a stock, N3EW needle, now in the top clip.. Someone mentioned the next leaner needle and I forgot, anyone got the info off the top of their noggin??

Thanks boys

Share this post


Link to post
Share on other sites
One of these days, I need to learn how to figure out those needle numbers and letters.

Indeed :) Me too

Share this post


Link to post
Share on other sites
N3CW is the next leanest followed by N3EJ and finally N3CJ.

Actually the the N3CW and N3CJ are the same needle except the CJ needle is slightly thicker which equates to a little leaner from full close to 1/8th throttle.

Same princible for the N3EW and N3EJ needles. (the fourth letter represent thickness of needle.)

The difference between the N3EW and N3CW is the taper starting possition i.e. there is 1/2 clip difference in the needles so you can tune the needle position in half clip increments.

Same princible for the N3EJ and N3CJ needles. (the third letter represents starting possition of needle tapper or clip possition)

Hope that some how helps

  • Like 1

Share this post


Link to post
Share on other sites
Actually the the N3CW and N3CJ are the same needle except the CJ needle is slightly thicker which equates to a little leaner from full close to 1/8th throttle.

Same princible for the N3EW and N3EJ needles. (the fourth letter represent thickness of needle.)

The difference between the N3EW and N3CW is the taper starting possition i.e. there is 1/2 clip difference in the needles so you can tune the needle position in half clip increments.

Same princible for the N3EJ and N3CJ needles. (the third letter represents starting possition of needle tapper or clip possition)

Hope that some how helps

When you say the CJ is thicker diameter, is it only thicker form close - 1/8 or is the whole length thicker with a mimicked taper??

All that being said, my half step leaner needle that I want would be the N3CW??

Share this post


Link to post
Share on other sites
All that being said, my half step leaner needle that I want would be the N3CW??

From your posts I think the simple answer would be yes, since N3CW clip #2 = N3EW clip #1.5, it will give you the richer clip position your looking for and should be a little less violent (amazing) than N3EW clip #1. Unfortunately you wont know untill you try.

Share this post


Link to post
Share on other sites

I run the N3CJ at clip # 2 on my yz250. I used to always run the N3EJ at clip #1 and it always ran the best there. But like you I wanted some adjustablility so I went with the next needle that was half a clip richer. I never noticed the N3EW being an improvement over the N3EJ, as it is only richer from 0-1/4 throttle. Hardly noticeably when you can tune the difference with the air screw. Sounds like N3CJ clip #2 is what I would recommend.

Share this post


Link to post
Share on other sites
I run the N3CJ at clip # 2 on my yz250. I used to always run the N3EJ at clip #1 and it always ran the best there. But like you I wanted some adjustablility so I went with the next needle that was half a clip richer.

This confuses me to some extent, I do understand the want for adjustability but can't figure out why if "it always ran the best" on N3EJ-1. CJ-2 when adjusted to 1 will be leaner than EJ-1, possibly too lean? Really it seems as though the best adjustability might be one of those 1/2 clip shims, then one needle becomes two or has 10 clip positions.

I never noticed the N3EW being an improvement over the N3EJ, as it is only richer from 0-1/4 throttle. Hardly noticeably when you can tune the difference with the air screw. Sounds like N3CJ clip #2 is what I would recommend.

You may be right about the air screw, but I think there's more to needle diameter than just that, most needles come in a variety of diameters even JD provides two. For me 0-1/4 throttle is the most difficult to jet, with so many different things contributing to this range it's no wonder. Things would be alot easier if I could hold it wide open. N3CJ-2 might work, again you won't know untill you try. If it were me I'd get both, for @ $14.00 plus shipping what have you got to loose?

  • Like 1

Share this post


Link to post
Share on other sites

i've already bought the two (2) needles... which are at my dealer's shop ready for pick up once i'm home again.

the simplest and best way is to just test them... nothing more.

i will install first the N3CW (at 2nd clip position) since it is half-step leaner than the N3EW, and the N3EJ, on the other hand, is half-step leaner than the N3CW.

i'm also at the current 2 steps leaner in pilot (45) and main (172) jets. prevailing temperatures by october in manila should be around 80ºF.

other than these, let's see what suits the bike.

Share this post


Link to post
Share on other sites

I forgot to mention that I also switched my PJ when I did my needle.. Im now running a 42 PJ, N3EW-1, and a 178 main with little to no spooge, no detonation.. Still wanna try the needle though, maybe even another half step leaner :)

Share this post


Link to post
Share on other sites

Ok gang this is good stuff, keep it up. I caution you to move slowly and pay attention though. I enjoy reading about these performance gains but would hate to hear about a meltdown. One thing I noticed when attempting to find the line between rich and lean was, some of the things that are said to have an affect on jetting, seemed to have a more noticeable affect the closer I got to that line. Bikedude you said no deto, I'm wondering if you've experienced any trouble with a hanging idle or surging during closed throttle decel?

Share this post


Link to post
Share on other sites
Ok gang this is good stuff, keep it up. I caution you to move slowly and pay attention though. I enjoy reading about these performance gains but would hate to hear about a meltdown. One thing I noticed when attempting to find the line between rich and lean was, some of the things that are said to have an affect on jetting, seemed to have a more noticeable affect the closer I got to that line. Bikedude you said no deto, I'm wondering if you've experienced any trouble with a hanging idle or surging during closed throttle decel?

No detonation.. BUT, I run a little race fuel and had EGorr mod my head for pump fuel.. Im sure those are contributing to my lack of detonation... :) I havent had a problem with my idle and actually, Im still not getting a lot of adjustment from my air screw and may try a 40 PJ :D Last time I had to go lean, leaner and leaner to run, I found chipped reeds.. Think Ill check those out before I get too carried away with my lean jets.. BUT, I dont have tons of jets LOL

Share this post


Link to post
Share on other sites
This confuses me to some extent, I do understand the want for adjustability but can't figure out why if "it always ran the best" on N3EJ-1. CJ-2 when adjusted to 1 will be leaner than EJ-1, possibly too lean? Really it seems as though the best adjustability might be one of those 1/2 clip shims, then one needle becomes two or has 10 clip positions.

You may be right about the air screw, but I think there's more to needle diameter than just that, most needles come in a variety of diameters even JD provides two. For me 0-1/4 throttle is the most difficult to jet, with so many different things contributing to this range it's no wonder. Things would be alot easier if I could hold it wide open. N3CJ-2 might work, again you won't know untill you try. If it were me I'd get both, for @ $14.00 plus shipping what have you got to loose?

The N3CJ is half a clip position leaner than the N3EJ. I went from N3EJ-1 which was on the very edge of too lean but ran great. So I am basically running the N3EJ @ clip position 1.5. I ride at 1000-2000' mostly but sometimes I take trips up into the mountains 3-6000'. If I ever wanted to lean it out I would have no room to drop the needle another clip position. I like to error on the side of being half a clip rich N3CJ-2 as opposed to running on the thin line N3EJ-1. I run 100% avgas @ 40:1 with Klotz R-50 and my squish has been modified.

I do not recommend just jumping to my settings and trying it. I have done several plug chops and piston wash readings to determine this being safe in my bike. Its all relevant to what your individual bike and location.

Share this post


Link to post
Share on other sites

and the N3EJ, on the other hand, is half-step leaner than the N3CW.

dt,

the N3EJ is not half a clip leaner than the N3CW. It is a slightly thicker needle which will make it leaner from 0-1/8-1/4 throttle.

The clip possition is identified by the 3rd letter (1/2 clip difference between E and C) and the needle thickness is identified in the 4th letter (J and W).

Therefore on the same clip possition the N3EJ is a half clip richer than the

N3CW but a little leaner on the needle diameter.

Hope that helps.

  • Like 1

Share this post


Link to post
Share on other sites

quick question. do you guys unbolt your swing arm to take out the carb every single time u want to rejet??? when i was doing my top end, i couldn't get the carb out without doing so.

Share this post


Link to post
Share on other sites
quick question. do you guys unbolt your swing arm to take out the carb every single time u want to rejet??? when i was doing my top end, i couldn't get the carb out without doing so.

Typically I just remove the rear sub frame at most. Usually just loosen all those three bolts and leave the bottom ones intact. Then I remove the top one to get the airboot to pull away from the carb by tilting the whole thing downward.:)

Share this post


Link to post
Share on other sites
quick question. do you guys unbolt your swing arm to take out the carb every single time u want to rejet??? when i was doing my top end, i couldn't get the carb out without doing so.

no, man...

i unbolt it only from the out-take side airboot and inlet port.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...