Running rich EC300

[thumperflipper]

on my 07 I jacked with all sorts of different needle/pilot/screw/main combos for a couple years, same problems you are having. I finally broke down and bought the JD needle kit and it still sucked. I called JD and he sent me a fatter needle, the rationale was my bike likely had very high time on it (I am the third owner) and the "needle jet" as he described it gets worn out from the needle going in and out of it. So he suggested a new carb OR to try a fatter needle (which he sent to me at no cost). In my case, he was right, and the fatter needle fixed it. Now it runs clean at all throttle positions

[swegass]

Interesting reading thumperflipper, yes I understand this wear of the needle jet cuz I have replaced many of them and also the needles in old car carbs back when I was a auto mechanic.
You say it was fixed with a "fatter" needle, I read that as if the needle have a fatter diameter and not as in a needle that gives fatter mixture??

Please let me know if im right.

Is there no way to change the needle jet (no spare part ?)

Lars

[swegass]

Hi Flashlight,
I had a N1EF in mine and now changed it to N1EG as it came with the bike and is supposed to be a bit leaner.
Not a big differance might be a bit more power when I'm on the pipe.
How does my N1EG differ from your N3CG?

[Flashlight]

The last letter "G" means a slightly leaner diameter so it will run slightly leaner around 1/8 - 1/4 throttle than an N1EF. Really not much of a difference between those needles.

The big improvement is in the taper profile. The N1EG or N1EF are too rich.

The N3CG has a leaner taper profile so it leans out 1/4 to 5/8 or so throttle which is what your bike likely needs.

The "C" is just a slightly richer clip position. The equivalent of being a half clip richer. The N3CG is identical to a N3EG with the clip half between the second and third position.

[Jakobi]

The diameter has next to no effect on the N1E series needles, because the straight section is so short that many bypass it entirely with a few turns of the idle screw (lifts the needle up onto the 1st taper).

[Flashlight]

Interesting, I knew they were bad, not that bad though.

I should add swegass, there is nothing special about a N3CG. It works for me and my bike. Enough that I stopped experimenting anyways.

Go over to the Intake jetting section of the forum and you will find many different kinds of jetting setups working. The N3CG (or N3EG) is just one that seems to work for many with older bikes.