Hi Jakodi, Thanks for the info, I live in Adelaide SA, I have changed the standard N1EF to a Suzuki N1EG but I have been hearing a bit about the N3CW, do u have the KTM part # ? we're running a 13 TZ250 Fantic that runs the GG engine.
11' 250 race-wa. jetting?
- Thread starter adv rider
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Hi Jakodi, Thanks for the info, I live in Adelaide SA, I have changed the standard N1EF to a Suzuki N1EG but I have been hearing a bit about the N3CW, do u have the KTM part # ? we're running a 13 TZ250 Fantic that runs the GG engine.
Jakobi
Super Moderator
Post some pics mate
Start a thread and we'll get the ball rolling! Fanticastic! Before you run off ordering alot of parts double check which model carb is on the bike. The AS2 and AS1 both jet differently. The AS2 has a shallow bowl and flat cap. The AS1 has a round threaded cap.
adv rider
Platinum Level Site Supporter
11' 250 jetting
I put another 2 hrs on bike yest., And it ran great. Temp was about 50-closer to 40 up top. about 1000ft. - in 6-8" of snow
I had made a minor change before the ride, and it seems to be just what it needed. I shimmed the needle .018".
So my JETTING IS NOW AT N3cw- #2 w/ shim, 42p, 180m,float height 8.7mm, air screw varies.
At end of ride checked plug, and its finally getting some color. Nice tan/choc color starting to show.
I put another 2 hrs on bike yest., And it ran great. Temp was about 50-closer to 40 up top. about 1000ft. - in 6-8" of snow
I had made a minor change before the ride, and it seems to be just what it needed. I shimmed the needle .018".
So my JETTING IS NOW AT N3cw- #2 w/ shim, 42p, 180m,float height 8.7mm, air screw varies.
At end of ride checked plug, and its finally getting some color. Nice tan/choc color starting to show.
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I too am looking at making some improvements to my 2010 EC250. Current settings are p40 N1EG #2 m180. Float height set correctly. Single 0.5 base gasket and standard unmodified head. Riding from sea level to maybe 500 feet in a mix of tight woods single track and open fire roads. It has been pretty cold here over the winter and I was happy enough to leave the bike rich as many of our rides were starting at first light and around 0 degrees C or less. Now that the clocks have changed and the temperatures are slowly rising, currently around 5-12 degrees, its time to get this thing jetted better. I would like to improve the initial response and get rid of that annoying spluttering and burbling it does after you come out of a tight wooded section and onto a more open bit where you can crack the throttle open. It always takes a few seconds to clear itself of unburnt mix and puts out a fairly impressive smokescreen! The bike does possess great torque and will tractor up just about anything and really gets going when it gets into it's stride. I was going to order N3C/EW and a Suzuki NEDJ for comparison. When I was talking to my local dealer, he happened to have an N8RH lying on the bench which he gave me to try in the meantime, saying it was a bit richer than the N3 but would give me an idea of how the bike would feel. When I pulled the needle from my own bike and compared it to the N8 I thought 'holy 5h!t that's a fat bugger!' especially at the tip, obviously much leaner than my current needle. I didn't fit it for fear of doing damage to the engine. Am I just being too cautious? Any input gratefully accepted, cheers
Jakobi
Super Moderator
Your dealer is on the money. The N3xx/N8Rx/N2Zx needles all share the same taper profiles. The clip positions, or starting points are what vary a bit. The diameters are the same across all the N series needles (N1, N3, NE, N0, etc)
Nxxx needle diameters
D=2.685mm
E=2.695mm (JD Blue)
F=2.705mm
G= 2.715
H= 2.725
W/I=2.735 (JD Red)
J= 2.745
K=2.755
In 1/2 clip variations from leanest to richest they are...
N89x=leanest
N3Cx
N3Ex
N8Rx
N2Zx
N4Dx
N3Vx
N4Ax
N6Mx=richest
So if you run N8RH#2 it would be similar to running N3CH#3, which is only a touch richer at 1/8th throttle than I generally recommend as a starting point. In regards to the tip of the needle there is a significant difference and thats because one is a 2 taper needle and the other 3 tapers. Simply make sure you go up a couple sizes on the main to compensate. 40 N8RH#2 178 should be a pretty decent starting position.
Nxxx needle diameters
D=2.685mm
E=2.695mm (JD Blue)
F=2.705mm
G= 2.715
H= 2.725
W/I=2.735 (JD Red)
J= 2.745
K=2.755
In 1/2 clip variations from leanest to richest they are...
N89x=leanest
N3Cx
N3Ex
N8Rx
N2Zx
N4Dx
N3Vx
N4Ax
N6Mx=richest
So if you run N8RH#2 it would be similar to running N3CH#3, which is only a touch richer at 1/8th throttle than I generally recommend as a starting point. In regards to the tip of the needle there is a significant difference and thats because one is a 2 taper needle and the other 3 tapers. Simply make sure you go up a couple sizes on the main to compensate. 40 N8RH#2 178 should be a pretty decent starting position.
Thanks for the info Jakobi, it has helped to make things a whole lot clearer. I already had everything buttoned up for this morning's ride before reading your post and, being Mr. Conservative, had set it up with p42 N8RH#3 and m180. This was a vast improvement over my original set-up but was still a tad rich on initial throttle opening and burbled a tiny wee bit but nowhere near as bad as before. No doubt if I had followed your advice we would have been pretty close. I didn't want to change the clip on the trail as conditions were somewhat muddy this morning and I didn't want to risk dropping some crud into the carb. A simple job for through the week. The bike was heaps easier to ride and picked up off the throttle really well meaning I didn't have to feather the clutch as much therefore less fatigue on the left arm. It pulled up all the hills better than before even if the revs dropped a bit it would still pick up again with a dab of clutch or a bit more throttle. All in all a good start, a few more tweaks and we should be there. All the other guys commented that it was great to be able to see where they were going without riding through a smokescreen! Cheers
Jakobi
Super Moderator
Top work Bazza. The N1Ex and NOZx needes have a really rich first taper which makes them really hard to clean up off the bottom. It tends to be the main cause of the excessive smoke and poor fuel consumption too.
Glad to hear you're in the ballpark. As always when we're discussing different settings across the world with different bikes, tolerances, environment, and fuels there will be some variance in what we all settle on. Up to you now to have a tinker and drill it right down. Just change one circuit at a time (pilot, clip, or main) so you can really evaluate the change its had on the overall setup, for better or worse.
Glad to hear you're in the ballpark. As always when we're discussing different settings across the world with different bikes, tolerances, environment, and fuels there will be some variance in what we all settle on. Up to you now to have a tinker and drill it right down. Just change one circuit at a time (pilot, clip, or main) so you can really evaluate the change its had on the overall setup, for better or worse.
I managed to get out for a couple of hours on both Saturday and Sunday this weekend for some more testing. I dropped the needle 1 position to #2 and left the 42 pilot in. Saturday was mostly tight in-the-trees stuff, 2nd and 3rd gear while Sunday was a couple of hours at a disused quarry which has a mix of tight single track and WOT blasts up to top gear. The change in clip position was noticeable and the bike ran cleaner off the bottom with no discernible burble or loading and still pulled strong onto the pipe and the top end. Hill climbs were no problem at all, the extra punch off the bottom giving plenty of momentum to pull up them with no bogging or loss of speed. The bike has really come to life and is a real blast to ride now compared to the old N1EG. It just picks up and goes now when you wind on the throttle and it's just so much more fun 
. It has also made the bike easier to turn and point in the right direction as I can now 'steer from the rear' more now because of the instant throttle response. Fuel economy is also improved; no figures but noticeable nonetheless. I could probably drop the pilot back to a 40 which would take me to what Jakobi suggested in the first place but I will leave the 42 in for now and see how we get on. Its just a pity that GasGas don't supply a few spare bits of brass with their new bikes. Thanks for the advice, it's much appreciated. Cheers. ps sorry for hijacking your thread adv, I really should have started a new one.
. It has also made the bike easier to turn and point in the right direction as I can now 'steer from the rear' more now because of the instant throttle response. Fuel economy is also improved; no figures but noticeable nonetheless. I could probably drop the pilot back to a 40 which would take me to what Jakobi suggested in the first place but I will leave the 42 in for now and see how we get on. Its just a pity that GasGas don't supply a few spare bits of brass with their new bikes. Thanks for the advice, it's much appreciated. Cheers. ps sorry for hijacking your thread adv, I really should have started a new one.
Jakobi
Super Moderator
Good stuff Baz. I still don't know why gg keeps sending carbs out with those N1Ex needles in them, and feel sorry for anyone who never tries anything else. They don't know what they're missing. In saying that there must be somewhere that the N1Ex needles work.. It sure wasn't in my bike though!
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