I'll be updating the other existing thread for official results (measurements and stuff)... but check this out:



DJ > N1 > Stock

N1TC appears to have same profile as stock, but is pulled way out with the notches!

 

A needle is a needle is a needle until it is measured up and/or a comparison run is made. I will say I won't be doing that, because the N1TC worked fine, especially with the carb set up a shade lean and the Dial-A-Jet. If you do some comparison testing I look forward to it and definitely say more power to you.

Kind of makes one wish an engine could be set up on a dyno bench like they can do with cars, then do the swapping of jetting with the ability to do so in an expedient fashion. That is the worst part of the stuff with bikes. It would be so much quicker, changing mains in a minute, needles in a few minutes. Back in the late 70s and early 80s real enthusiast magazines like Cycle actually did stuff like that with the more popular niche bikes, like a two issue Yamaha SR500 article Gordon Jennings did. He not only jetted in a Mikuni, but did another couple carburetors besides that, plus exhaust systems. Had the bike on a dyno and an easier set up to work with.

I have to give big credit to KLXter and Richard Avitar for work they do - ever time they do the changes the bike has to be taken apart to get in there. That is the worst part. It would be a breeze if the set up was like that Yamaha SR500 Jennings did, where the main jet can be changed on the bike and carb took only a few minutes to remove, but that isn't the case anymore. Check this out:



Don't you wish you had that room on the KLX! (By the way that non-pumper was what kept me thinking one can be done on the KLX.)

It takes more time than that to adjust the idle mix screw, buried up underneath on some carbs. Plus the media does no hop up articles on anything. It takes a few with the time and desire to do the work now. I used the Kawasaki parts because they had been documented to work well. Back ni 1988 I used Gordon Jennings' guidelines in doing my SR500, because it was documented to work, most specifically the 1-5/8" ID x 33" long (if I remember right) exhaust when I made my pipe.

That is why in another jetting thread I mention doing the on-line research on the TM36-68 to try to find a working generalization to start with. After 6 years there is starting to be a general set up for certain areas, that works. It just hasn't hit any common knowledge sort of listing yet.

Fact is a "sticky" thread should be made for each carb, the Kiehin CVK34 and the TM36-68, enabling riders to look in the thread and see what riders in similar circumstances are running in their carbs. That would get a rider close enough they should be able to get a rideable set up within one or two tweaks of being a good set up, as good as possible without having special equipment. One main jet step in either direction or one notch on the needle, but very close to correct to start.

That used to be the case with some magazine how-to articles. Interesting enough, now some are doing it with suspension, how many clicks on damping for each model. I guess the lawyers say it is okay to do that.

 

Here's the comparisons in standardized measure and from the seat of the clips:
https://i.imgur.com/HFsmAnL.png

 

The first chart can be used to quickly verify a needles' contour.
The second chart is for making determinations of fueling curves - therefore possible "best" applications.

Some observations:
N1TC is initially leaner (.094 vs .091 straight sections) but with a shorter straight section ( .17 shorter to initial taper ) - the initial taper is extremely slight though - In fact, at same distances from clip , the taper O.D.'s are practically identical.

On top end fueling - the N1TC is over a tenth inch shorter (.11) but carries a larger end O.D. (.049 vs .046) and a longer "tip" (.040 vs .011) compared to the same point of overall length on the DJ0228 and its' "tip".. So, perhaps it is same or slightly leaner from 7k to redline ?

Off the top of my head, N1TC could be a good choice when lidless, using stock cam timing, and slip-on, but only if the main jet is properly selected for best power 7k-redline. In this case, the larger O.D. straight section will preserve throttle response with large or small snaps on the throttle from 3-5k, and the clip position would control when additional fueling begins as RPM's rise..

With the above but adding MCM, I will need further dyno testing of DJ140/3N and DJ140/2N (near sea level) to make an opinion..

If running slip-on but with lid, a much smaller main jet would be needed and N1TC would likely work as well as the DJ0228 at all clip settings but run leaner at RPM's below about 4K..

 

I actually owe the riders who originally did the original N1TC jetting when there was no DJ kit and the bike was new. They took a chance that the KLX300 needle would work and it did.

There was enough positive feedback on that set up since 2007 and virtually no negative, along with the pilot and the main, that it was a no brainer for me. I wasn't breaking any new ground, someone had already done it about 8 years back. From my research, numerous others tried and proved the combination worked. I'm just one of the masses that did the search took the positive feedback and used it.

The numbers do show the DJ needle is almost identical to the N1TC in the taper. Not totally clear on the relativity of the numbers. A chart with indicators would absolutely clarify it. The second chart makes it appear the N1TC is richer at low throttle openings if the taper is higher at the top of the needle on the DJ as it appears by the start of taper number.

The stock one runs close, but would need shimmed to come close to matching the other two, but is leaner on the top (which would be low throttle opening and cruising range maybe). The OEM needle could be used if shimmed, but would be lean at smaller openings. Pretty much what I experienced when took a chance to save a buck with a .030" washer on the stock fixed needle. I got the N1TC and no problems. Shoulda paid attention and done it all the first time.

But no regrets taking the short cut doing the research and using what was proven to be good from the start... I hate taking a carb off and on and off and on...

 

For what it is worth, by butt, I know an 06 rider, with KDX snorkel and 300 pipe/no baffle, and myself on my 09, with stock exhaust with KDX snorkel and MCM, that have excellent experience with the N1TC in clip position 2. The bikes run clean and strong. The Kiehin main at a 125 or 128 is in the park for sure.

But since hard jetting has a pretty much fixed flow, both of us took the easy way out and "injected" additional fuel/air mix with the Dial-A-Jet. I actually got him to do it - gave him my kit for the SR. He ran it without for a while, then found the performance smoother and stronger after installing the kit. Again based on on-road and off-road experience, no measurement equipment, just the old school riding, although I've done comparisons on plug color and exhaust tip color on the 650 with modifications and weather/temp/elevation differences. There may be a bit of horsepower missing, but no bogging, no hesitation, no gray smoke, just crisp performance.

 

I found that changing jets seemed easier if I left off the shrouds & side covers whenever I thought I'd probably be making some changes instead of re-installing all that each time. If you substituted a section of hose and a K&N universal round air cleaner for the stock boot temporarily you could eliminate the hassle of reconnecting the air box boot as well. Maybe have it sticking out the right side a bit to avoid the exhaust heat and maintain the same inlet length as stock.

Don't bolt the seat down if the testing is just a quick ride down the hwy. I think I used one bolt sometimes instead of 2.

Then it's just the tank/petcock and carb.

 

I have considered some sort of heavy plastic or metal water bottle, with a fitting in the cap for fuel feed, as a temp that could be temp attached (aka bungee) on the frame. I haven't been to WalMart or some place like that to see about it. Perhaps that is my errand today. I considered looking at some of the heavy water/soft drink bottles too. Make a temp tank to wire, bungee or velcro tie to the frame for short runs.

I figure some sort of fitting can be worked up in the cap to fit the fuel line, maybe an in-line petcock if I can find one cheap. Just haven't quite done it yet. I have to clean up the 650 from storage for the winter - rain and crap has kept it tucked away in the trailer until last week. I have to clean off the rust inhibitor and last year's dirt. Wife's gone for the week so I have time to dink around for the tank stuff and do some bike stuff... still rainy.

 

I pull the carb out thru the left side without removing any shrouds or seat. It's tricky but once you get the hang of it is simple to do. I can Pull the carb off, make a change to needle or main and reinstall completely in 20-30 mins. I got the idea from someone on here but I can't remember who now.

 

You'll have to remove the throttle cable bracket though I'm sure.