JD Jetting Kit or Experiment

[Fred1956]

Originally Posted by Jakobi

I'll be keen to hear what they've jetted your bike with too Fred. Sounds like you're loving the new ride!

New springs will be here today so I pulled the bike down last night, here are my carb specs. I'm in NW Arkansas at @1200 ASL (I think)
2010 EC250 Six Days ASII 38mm
MJ-180
PJ-42
Needle- JD red #3
AS-1 7/8 turns out
Slide-#7
Idle screw is wound in pretty good-2 1/4 turns out from spring bottom yields .737mm slide opening at idle
Bike starts great, idles good, & runs great if I had a squeak it would be that on a long steep climb, if I hit it in 3rd I get caught at the very top needing to clutch or shift down. Other than that no complaints. I am going to drop the float a bit as it looks to high to me. (see pic) BTW I do have the squish corrected but haven't measured it yet.
Jakobi- what would a NEDW do to this setup?

[Jakobi]

Good info Fred.

Can you give me a few weeks to get back to you on the answer?? I am yet to put a JD needle anywhere near my bike to date, however Simmo737 has been kind enough to have his wifey mail his JD red across Australia for me. I was thinking of starting in clip 3 with 40/178 and taking it from there.

I'm currently running 40 N3CW#3/N3EW#2 178 which I think is very similar to JD Red. Same straight section diameter. The JD is slightly thicker at the pointy end, and JD has a middle taper but I'm not sure if its richer or leaner at this point. I suspect it might be leaner from everything I have read.


I tried 40 NECW#3 172 the other day and found it a touch rich in the lower mid (coming into the middle taper). I think a half a clip pos (NEDW#2) would have been ace. I didn't try it though as I was getting the bike ready for a ride and went back to what I knew worked well.

[Edman]

I recieved my jets but no needle yet. (170/172/175/180 to play with)
I have a NEDJ and N3CJ coming. Probably start with NEDJ first.
Also I noticed they sent me a 48 Pilot. Reordered a 40 and 42.
I will have to research on how to adjust slide. I don't have a clue now but will figure it out with some reading.
So, I'll post an update when I can.
Thanks Fred for update.

[Jakobi]

Not sure what you mean by adjusting the slide. Basically to set the idle you want the slide to be only just open. The slide height is set mechanically by the idle screw so if the idle screw is wound right in, it holds the slide up high. If its in enough (slide heigh enough) you can effectively bypass the straight section of the needle which will cause inconsistancies and make the pilot and airscrew very much unresponsive.

Below is a pic of how my bike is set to idle. Should have taken a measurement like Fred did when I had the carb out. I also really think I need to make one big sticky for the 2T section with all the info in it re needles, diameter sizes, comparisons, float heights, etc. Seems to be alot of info spread through many threads.

[Jakobi]

You may also be able to get it to sit a little lower again than mine depending on if you have a notched slide.

[Edman]

What does slide #7 mean? Jakobi, I understand what u mean by idle screw lifting slide up. Again, I am a novice with jetting, or carbs in general, but it's clearing up a bit.
I think u should do a sticky. It would be nice to have everything in one place.
Thanks

[Fred1956]

Originally Posted by Edman

What does slide #7 mean? Jakobi, I understand what u mean by idle screw lifting slide up. Again, I am a novice with jetting, or carbs in general, but it's clearing up a bit.
I think u should do a sticky. It would be nice to have everything in one place.
Thanks

There is a number stamped on the slide that represents the cutaway angle of the slide, #7 seems to be the most common one but there are others. Slides are more expensive to replace but knowing what slide you have helps when giving recommendations for jet or needle changes

[Jakobi]

Yep! See the little star and the number on the bottom of the carbs just above the hole in the pic. The number represents the angle of the cutaway on the bottom of the carb. Lower numbers are richer, higher are leaner. The slide cutaway is active below 1/4 throttle along with pilot, AS, needle diameter etc. Part of the reason why small throttle openings are the hardest to get 'just right'. At $50ea you tend to just work around them with different needle diameters, but sometimes you can't, and as Fred said its another piece of the puzzle when asking for help.

[n_green]

Originally Posted by Jakobi

Yep! See the little star and the number on the bottom of the carbs just above the hole in the pic. The number represents the angle of the cutaway on the bottom of the carb. Lower numbers are richer, higher are leaner. The slide cutaway is active below 1/4 throttle along with pilot, AS, needle diameter etc. Part of the reason why small throttle openings are the hardest to get 'just right'. At $50ea you tend to just work around them with different needle diameters, but sometimes you can't, and as Fred said its another piece of the puzzle when asking for help.

Sorry to hijack but is there a "magic" slide number on these bikes? I seem to remember a 7.5 instead of a 7 slide was meant to fix some bottom end niggles on the KTM's. My '11 GG 300 (36mm carb) is fitted with a 6.5 notched slide?

[Edman]

Today put in 40, 172, NEDJ, AS 3 turns, slide is a 6.5. Idle screw screwed out about 1/2 way. Also adjusted float a bit.
I plan to read more tonite to see what to look for to see if I need to put back in the 42 or 175. I might could use 38 Pilot to get A/S turned in alittle. I also have a N3CJ I might play with.
Bike ran much better. Less smoke. Idled better. Drove in neighborhood so couldn't really test it, but less bog at bottom, although seemed alittle weak . Mid range very good and strong, and 3/4 seemed good. Not much riding WOT but seemed ok. Hopefully can take it out tomorrow to see how it really does.
Bike had a slight knocking sound at idle, but smooth sounding with alittle throttle.
Carb had 42, 175, forgot what needle but original needle.
But well pleased so far!
Thanks Jakobi, Fred and others who helped with info and suggestions.
Eddie