2010 Jetting Saga Continues

[Bailey28]

The popular CCK needle with a 38 pilot and a 175 main jet as compared to Jakobi's N3CH. I kept the pilot at 38 for both. Don't worry about the rest of the entries as they are not complete and not showing. The reference line again is the N1EF clip 1, 38 pilot 175 main. My bike spooged a lot with the CCK, although it made more torque.

If keeping the triple taper needle works well above idle, maybe just getting a thicker needle as in Jakobi's case, F to an H, works well to keep the idle area clean.

[Bailey28]

Here is the profile comparison for the N1EF-1 and the N3CH 1. Notice the N3CH is a double taper needle, it does not have the extra rich taper from 3/4 to full throttle. N1EF is in black and the N3CH is in red.

[Bailey28]

This graph is interesting. I took the N3CH, made the diameter an F for comparison sake, and overlayed it onto an ACL needle profile.

If you compare an "A" 1*00" aftermarket taper to the first taper in the N3 series, they match perfectly. An ACL-3 is equal to an N3CF-3 until just above 3/8 throttle. After that the N3CF taper changes to a "C" 1*34" taper at that point. No surprise that the aftermarket needles follow a single taper of any of the double and triple taper needles.

In fact the first taper of our beloved N1EF needles is even more shallow than the "A" taper. This gives only a slight richening over the first part of the throttle. It is almost a straight portion.

Now if I could only find that little Orphan Annie decoder pin.... yes I drank my Ovaltine!

[mrkartoom]

Originally Posted by GMP

What slide are you guys (with the same size carbs) running? If the slide is rich you can screw with needles forever and never get it really good. It will also mess with your pilot ckt as you have to jack the idle screw in. Try a leaner slide and by all means get the squish dialed in when you can. 300s are more touchy than 250s and these details are even more important.

Also, you should jet with the map switch in the hi or sun mode (more advance).

38mm I'm in Sun mode and using the 7.0 stock slide. Are some running 8's or 9's? I've seen others running richer, but that have been on 36mm. Something is messing with my a/s for sure.

[Bailey28]

I installed the o-ring and washer from a four stroke fuel screw onto my air screw to get it to stop leaking premix all over the float bowl. I think the o-ring and washer made the screw adjustment hold better, as it is more consistent.

[Jakobi]

Originally Posted by mrkartoom

38mm I'm in Sun mode and using the 7.0 stock slide. Are some running 8's or 9's? I've seen others running richer, but that have been on 36mm. Something is messing with my a/s for sure.

+1 38mm PWK ASII - Always sunny. 7.0 stock slide.

I have run with the pilot as large as 42. All that happens is that I get the tell tales signs of a rich bike. Loads of smoke, spooge, loading up of the plug, excess fuel consumption, and as soon as the bike is warm it won't idle until the idle is screwed in far enough to bypass the pilot circuit.

In saying this the N3EJ is considerably leaner on the overlap of the pilot. I will try a 38 at first and may move onto a 40. As stated earlier/in another thread, a friend of mine is using a 35 pilot with great results. Just have to confirm what needle he is using.

Bailey. Could you please post a graph showing comparison between these needles.

Base - 38 N3EG #1 175
38 N3CH #2 175
38 N3CH #1 175
38 N3EJ #2 175
38 N3EJ #1 175

that would be ace!

[Bailey28]

HERE: all of your needles are very close to one another. the
j diameters are leaner on the straight but other than that, not much difference.

[Bailey28]

I think the N1EF would be a fine needle if the L1 were longer, as in something less than or longer than the 1st clip, like an N1EF on clip -2

The initial taper of the N1Ex series is so mild and shallow that it appears that it would not affect the off idle richness as much. I think that is why Jakobi and others have gone to a larger diameter to help cure the richness at idle.

I think the bike would idle well running on only the pilot circuit and with minimal intrusion from needle pullover.

I would like to try a N1EH or N1EJ with a 38, 40, and 42 pilot.

[Bailey28]

Ok, just fooling around with the program, here are the comparisons so far:

Base Needle: N1EF clip 1 all needles compared to this one!

N85F clip 3 is the same as N1EF 1 everywhere

N4AF way richer from 1/8 on, then leaner at 3/4 on (2 taper)

N3CF leaner 1/8 to 3/8 then leaner from 3/4 on (2 taper)

N4DF leaner at 1/8th, richer at 1/4, then leaner at 3/4 on (2 taper)

N3EF leaner at 1/8, same at 1/4, leaner everywhere else

NAFF richer from 1/4 on but same profile as N1

NALF way rich at 1/4, same profile as N1

N6MF richer at 1/8 only (2 taper)

N8RF same needle as N3CF on clip 2

NFTF leaner at 1/8 then very rich at 1/4, follows same profile as N1 but rich

N3VF rich at 1/8, then leaner at 3/4 on (2 taper)

N3WF leaner from 1/8 to 1/4, then exactly the same as N1EF1

N2ZF 1/2 clip leaner than N1EF1

NOZF same as N1EF1, 1/2 clip leaner as well.

There you have it... The N1EF taper has the longest straight section of any of these here with the exception of the N3CF and EF tapers... however the N3 tapers take longer to get to the richer midrange taper than the N1 does, which could cause a flat spot in the midrange.

[Jakobi]

Heres the sound of 38 N3CH#1 175 after my test ride yesterday. Obviously its on the stand so doesn't count for much. Will try and get some audio/video of riding either this afternoon or over the next few days

http://www.youtube.com/watch?v=UZkzUAOKy_0