necj is it any good ?

[britishgas]

i have a gas gas 300 2012 racing , i ride in the uk avtemp 10c i have been advised to use an necj 38 pilot 165 main jet , i currentley run 45 pilot,175 main n1ef 3rd clip, what will the differance be ?.will it be any better on fuel consumption , and is there a better option for me ?
thanks in advance britishgas

 

[Jakobi]

Who advised such things?

I'm an advocate of the NECJ needle, but I wouldn't start with a 38 pilot or a 165 main on a stock engine. Too much of a jump from where you are with the stock needle. The setup you listed is considerably leaner across the board so you'll definitely see an improvement in response and fuel economy (assuming you're too rich now, and that the settings not too lean).

I'd personally start more around a 40/42 pilto, NECJ#3, and 172/175 main. This will give you a base to start from that is safe.

Recently Dave at TSP set up a 2013 on the Dyno and said he had it at 40 NECJ#3 165, but he'd also milled the head, reduced the squish, reshaped the band, and adjusted the compression ratio. Effectively improved efficiency so no surprise it can get away with a leaner setup.

 

[britishgas]

Who advised such things?

I'm an advocate of the NECJ needle, but I wouldn't start with a 38 pilot or a 165 main on a stock engine. Too much of a jump from where you are with the stock needle. The setup you listed is considerably leaner across the board so you'll definitely see an improvement in response and fuel economy (assuming you're too rich now, and that the settings not too lean).

I'd personally start more around a 40/42 pilto, NECJ#3, and 172/175 main. This will give you a base to start from that is safe.

Recently Dave at TSP set up a 2013 on the Dyno and said he had it at 40 NECJ#3 165, but he'd also milled the head, reduced the squish, reshaped the band, and adjusted the compression ratio. Effectively improved efficiency so no surprise it can get away with a leaner setup.

i will give it a go with a 40 pilot necj, and 175 main will the needle also make it leaner ? cheers jakobi

 

[Jakobi]

The needle covers the largest portion of the throttle including the area you spend the most time in. This is where you'll see the economy gains. Compared to the stock setup its leaner off the bottom, fills in a bit of a lean spot in the midrange and is about the same up top.

 

[GasTimppa]

Worth of trying.

 

[celler]

I found the NECJ a little lean on my 300 with a 38 carb. Always seemed to be lean on bottom even going up to a 48 pilot. I prefer the Nedw Suzuki needle. I use the Necj in my 250 KTM with a 36 carb and it works great,

 

[Jakobi]

Yeah should mention all my testings on Australian 98Ron fuels in hot humid tropical climates 300-900M. You might need to work through a couple different needle diameters and clip positions to find whats best for you, but it won't be far off.

 

[Tom250]

hi folks, i used on my 2013 300e a NECJ#3 all year and found out that on 42 idle and 168 main it ran pretty well, had big punch right from the bottom, much more torque comparing to standard and has good snap. but still was oiling out the muffler, it ran great on idle and i never had any problem with boiling. i tried 40 idle, was to lean, also i tried second clip from top, also to lean. a tank with 10,5liter is good for a 110km ride. from my experience the NECJ isnt "the" needle to use.

i ordered now a CEK and im curious how it will perform.

 

[webmaster]

Go with the richer pilot and back down and reset your idle screw when making the swap to a better needle. The idle screw shouldn't be "coil bound" if you are set up correctly.

Another symptom of "pulling over" (too lean pilot and low end fuel supplied by needle pulled up...) - symptom is that idle mixture screw has little effect. With the proper setup and settings you should be able to dial it in so it's clean "off the bottom" with the idle mixture screw - instead of always hunting for a leaner pilot.

jeff

 

[britishgas]

what will be the differance would there be between the necj and nedw?

 

[Jakobi]

NEDx is a half a clip position richer than NECx (1/4 throttle to 3/4, most noticable just past 1/4 throttle)
W diameter is one step richer than the J (idle through to 1/4 biggest influence at 1/8th).

 

[britishgas]

i have now bought a nedw which main ,pilot and clip do you recomend .
cheers british

 

[Jakobi]

40/42 pilot, 172/175 main. I'd start with whats in the bike (if stock likely 42/175) and then adjust as required.

 

[britishgas]

nedw just has one slight problem in top gear when i try too open the throttle from almost closed it does not pull cleanly from low revs its fine once its on the pipe , i am using 175 main 45 pilot needle on third clip ?

 

[Jakobi]

Is it breaking up rich, or falling flat? Use the choke to see if it improves or worsens the situation. Or move the needle 1 clip richer, go for a ride. Improved or not. If better great, if worse move it back the other way, ride and evaluate. One change at a time.

Remember its always going to be a compromise too. Very different engine loads pulling from low in the revs in 1st gear compared to 6th.