LT racing jet kit report...

[jimbolaya]

I've finally gotten my #8 slide installed on the 300 and I'm happy to say it has done exactly what it was supposed to do. The low end throttle response is completely clean and with my airscrew adjusted for the temp of the moment it runs as good as it can. Having the head redone might make things work even better, but for now performance of the engine is fully acceptable.
Color me one happy camper

[GMP]

Glad it worked out for you.

[jefgil123]

Thanks for the CCK suggestion. It is smooth.

I had gotten the head squish tightened up and although the milled head noticeibly improved the low end power , it also accentuated the flaws in the stock jetting. (#38, N1ED #2, 180) The hit right off idle with the stock jetting was then a handful in tight woods. The CCK will be a big help with smoothness.


2001 300 XC

[gasIdaho]

Now try the RB Designs carb mod. You will be amazed. The low end tunability range is huge. Top end is sick fast...

[tonipurhonen]

Originally Posted by pobit

I received a few emails asking me to clarify how these needles differ in feel so below is a fuller description. These settings are for sea level, 70 degrees, tested in a 06 DE300 and a 06 DE250. The bikes are American DE models with the lighter ignitions, stock GG pipes and FMF Turbine Core II mufflers. The motors are stock with stock base gasket height and RBD head mods. The stock #7 slide was used for all needles. Pump gas 91 octane, oil mixed at 40:1

45 pilot LTR-0#3 175 main:
Slightly lean at 1/8 to 1/4 throttle giving the bike a hit at off idle and then the richer end taper makes the bike feel weak from mid to top in the 300. The motor will idle cleaner with a 42 pilot but this makes the 1/8 to 1/4 throttle hit even harder. Works better in the 250 than the 300 as the 250 is still able to spin up with the richer end taper and the hit at off idle isn't as strong. If LTR would radius the transition from the straight section to the taper to soften the hit, it would be a good needle for the 250.

42 pilot, CCK#3 178 main:
Very smooth, easy to control, torqy power from bottom to top with no hit anywhere. Works in both 250 and 300. Good choice for those that prefer throttle control for picking your way through rock gardens or tough survival rides. This needle also works well for novice racers who get tired before the end of a race and struggle with throttle control.

42 pilot N3EG#3 175 main:
This needle is for racers and gives the 300 the most power with a strong mid to top pull. My 300 has the dual ignition and this needle in the MX mode makes for a lot of mid to top power. For slower, tight riding, I ride with the ignition in the rain mode and this takes the edge off the power and makes it more controlable. In cold weather you will need to use the 1/2 clip richer N3CG#4 with a 178 main or you will get a little rattle from mid to top. These needles do not work in the 250 as these needles are too lean on the end taper and make the 250 too revvy. I race A class and this was my favorite for my type of riding.

45 pilot JD red#3 175 main:
This needle in the 300 feels like the N3EG needle on the bottom but does not pull as strong from mid to top in the 300. You get a clean bottom pull with a more torqy, mellow mid to top pull. A little too mellow for my taste. In the 250, it gives the bike a torqy mid to top and doesn't hurt acceleration. This would be my first choice in the 250 although at $80.00 for the kit, it is way over priced. For about $7.00 you can make your own crude JD red copy from a DDN needle. This needle has the same straight section diameter and a 45 degree taper simular to the JD's end taper. Chuck it up in a Dremel and sand the transition from the straight diameter to the taper at 34 degrees. This will make it a multi taper with the first taper at 34 degrees and the second taper at 45 degrees. The JD red is slightly lean in cooler weather at off idle so If your going to make your own, A DDL may be a better choice with it's smaller straight diameter. DDK has the same diameter as the JD blue.

Hope this helps, Dave

Which one the following needles N1EC N1EF N1EE N1EG N1ED is most similar to the N3EG#3 needle. I live in sweden any idea where I could buy a N3EG needle.

//Toni

[widebear]

Toni. You can also try a N3WF or a N3YF , They are powerjet Kawi needles 99-02 I believe. The YF works very well in my 300 but when we tried the same in cactusreid's 300 it would barely run. I'm thinking it may be partly due to his needle jet being worn out of spec.

[jeffd]

FYI - keihin doesn't sell a replacement needle jet (aka nozzle) so there wasn't much you could do to compensate for wear in this part. Options were to try leaner needles or just throw in the towel and buy a new carb.

A while back, I mentioned this problem to Ron at RB-Designs and he came up with a solution. He is making up the replacement needle jets that keihin doesn't supply. This old "nozzle" needs to be pressed out of the carb and a new one pressed in. The jet block needs to be removed in order to accomplish this - so you have to send your carb to him to have the work done.

I took a look a quick look at Ron's website, but don't see that he has the "nozzle update" listed - his other gasgas carb mods are listed here...

http://www.rb-designs.com/gasgas250-300.htm

jeff

[tonipurhonen]

If I have access to these needles N1EC N1EF N1EE N1EG N1ED how should I jet to get my ec300 run best.
I would be glad if I would get some help in summer and winter jetting.
I live at sea level, in summer time the temp. is round 18 celsius in winter -7.
This summer I have used the following jetting.
Slide #7
42
N1EF#3
175
With these jetting I have a slight hesitation when giving full throttle from low RPM's in the midrange.

[RBD]

Originally Posted by jeffd

FYI - keihin doesn't sell a replacement needle jet (aka nozzle) so there wasn't much you could do to compensate for wear in this part. Options were to try leaner needles or just throw in the towel and buy a new carb.

A while back, I mentioned this problem to Ron at RB-Designs and he came up with a solution. He is making up the replacement needle jets that keihin doesn't supply. This old "nozzle" needs to be pressed out of the carb and a new one pressed in. The jet block needs to be removed in order to accomplish this - so you have to send your carb to him to have the work done.

I took a look a quick look at Ron's website, but don't see that he has the "nozzle update" listed - his other gasgas carb mods are listed here...

http://www.rb-designs.com/gasgas250-300.htm

jeff

As Jeff mentioned above, I do make a replacement needle jet for the Keihin PWK 38 mm carbs.

I machine these nozzles from C360 brass stock. I do this repair for $25.00 plus return shipping and handling.

Ron

[pobit]

Originally Posted by tonipurhonen

If I have access to these needles N1EC N1EF N1EE N1EG N1ED how should I jet to get my ec300 run best.
I would be glad if I would get some help in summer and winter jetting.
I live at sea level, in summer time the temp. is round 18 celsius in winter -7.
This summer I have used the following jetting.
Slide #7
42
N1EF#3
175
With these jetting I have a slight hesitation when giving full throttle from low RPM's in the midrange. Which one the following needles N1EC N1EF N1EE N1EG N1ED is most similar to the N3EG#3 needle. I live in sweden any idea where I could buy a N3EG needle.

All the needles you have listed are the same needle with only a differant straight diameter. None of them will work. The needles you listed have a rich spot at off idle that makes the bike stumble and a rich end taper that makes the bike run flat from mid to top.
The N3EG needle is an optional needle for an 03 Yamaha YZ250 two stroke. The needle for a 99 Honda CR250 part# 1369D it is identical to the CCK except it is 1/2 clip leaner. CCK#3 = 1369D#3.5 These may be easier for you to get than ordering needles from the USA. Dave