ec300 jetting
 

Ive just had my carb apart and have found a no6 slide with NE1EE needle 35 pilot and 178 main. This is on my ec300 with gnarly pipe. Does anyone know if this is the standard jetting? Other people seem to favour the no7 slide, do the slides realy make much diffrence?

Yes, the slide cutout makes a difference. If you have the EC head, I prefer a #8 slide. With an XC or higher compression head, then the #7 is my choice. It looks like the bulk of the people satisfied with their EC300 jetting use 40-45 pilot jet.

Needles? I was quite happy with my LTR needle and #8 slide. However, have a higher compression head now and more low end. I dropped a tooth on my rear sprocket and went back to the stock #7 slide. The bike was great, but I got a CCK needle to test out. So far, I'm in the leanest clip position based on my street runs. (My bike is plated) I need to ride it in the dirt to see if I will like it. It runs strong with only a slight hesitation coming onto the pipe if you let it pull from the basement to the penthouse. My upcoming dirt ride will be a better test.

Running this jetting the plug was a light brown colour after an hours trail ride, so that is sugesting the jetting is ok. I was mainly woried about having such a small pilot jet as I have read that it isnt recomended going under a 40. Am I getting away with this beacuse of the no6 slide im using? I believe the no6 to be richer than the 7 or 8. Does anyone else use a no6 slide?

I don't know anyone riding a GasGas250 or 300 with a #6 slide. From what I read here, the EC200 sometimes is stock with a #6 slide.

I rode a little over 40 dirt miles with the new needle. I started in the leanest clip position. My bike ran great, but the bike reved past the sweet spot of the power a little too quickly. I dropped the clip/raised the needle and slowed the revs down a little and rode most of the day like this. The power is linear, but it rips onto the powerband with just a flick of the wrist. The power is very '99 YZ400 like, but with more low-end. Mikey Likes!!!! Now, I just need to test the next richer needle position and also with my #8 slide.

You may missing some performance that you don't know that exist with your current jetting. However, if your happy with what you have, then good for you. There are no "set in stone" jetting specs for our bikes. If you search the site, you will see the bulk of riders here using a 40 or 42 pilot jet. It also appears the bulk of the riders using a #7 slide. Needles? do a search... Main jets vary the most, and I seem to run leaner than most with a 172 at sea level.

Mike Baxter

Ok thanks for your help, Ive just changed to N1EF on 2nd clip in no7 slide 40 pilot and 178 main gonna give that a try, When its daylight and its not raining!! I hate british winters!

That's a more typical British setup.
I'm trying 42, CCK on middle, 180 main but like you waiting for some decent weather to test which will be enduro training at Weavers Down I think. Unfortunately it's not taxed and tested so can't even try on the road. Can't be bothered to find an open MX track in this awful weather.

Nice, let me know how you get on with that set-up. My bikes road legal as Im keen on green laning, Hoping to test it out on sunday!:D

I have 2006 EC300.
I run N1EF needle on clip number 1, 42 pilot and 178 main. Slide is std (number 7 I think). I run rock-oil fully synthetic 2 stroke oil at 45:1 and the bike is sweet. It even idles properly :D
I ride at sea-level to about 1000 ft. Never an issue with starting or fouling plugs.

Bike has FMF gnarly and powercore 2 pipe.

My bike didnt idle with the previous owners settings, I wasnt keen on having that no6 slide in there. I also have the gnarly with power core 2, I will try the 42 pilot if im not happy with the 40.:)