'09 EC250 Jetting - Baseline help?
 

Helping my brother-in-law as this is his first 2T and I just checked everything yesterday. I looked through the jetting thread and it appears as if the 180 MJ is pretty common for our temp/elev, but I'm wondering about the PJ and the needle. This is where we spend most of our time since it's tight and technical.

180 MJ
N1EF #3
40 PJ
#7 slide
A/S 1.5

Temps in the 60-70s
Typical riding elevation 1500 - 3500 ft

I took a quick rip on his bike and the first thing I noticed is holy CARP it pulls like crazy; it's almost too much power when on the gas through the first 3 gears...front end doesn't want to stay on the ground. I'm hoping there's something I can do to tame this down some?

There was bit of drool coming out the pipe and it's not the Q-Stealth (Turbine Core) - might be a little rich?

I also noticed there isn't a smooth transition when going from 1/4 throttle to 3/4; slight burble and hesitation.

Any input or pointers greatly appreciated...I'm just barely ahead of my brother-in-law when it comes to jetting...lol.

Ok, I've read through a whole bunch of threads and they lead me to believe I need to swap out the stock needle with a Zuk or Yam needle - though I'd like to ask for some help before doing so.

The bike has the old screw-style top carb and it's an '09; would this be the ASII or ASI carb? I should have looked this morning as the bike's torn apart in my garage, but I forgot.

Since it's the screw-top carb, I think I need to go with one of these needles:

N3EG from this thread (http://www.gasgasrider.org/forum/showthread.php?t=13352)

Or would perhaps one of these would be better:

NECW or NEDW from this thread (http://www.gasgasrider.org/forum/showthread.php?t=12546)

Jakobi - can you lend any assistance here...please :o ? I want to get a couple needles to play with for testing. The stock needle is harsh and it sounds like many have experienced better performance with one of the three needles listed above. Since I'm spending my brother-in-law's money, I'd prefer to get a couple and not go overboard...lol.

Here in Australia-o, one of my mates has an 09250R. Pretty sure he ran around 38/40 N3EG#3 180 on a modified head.

The Suzuki needles should work too, and I'd recommend very similar 40 NEDG 175/178.

The older carb just needs to be jetted a little richer across the board.

I know several others speak very highly of the JD Blue needle in the AS1 Carbs as well. Might be able to source one of these cheaply of another member who's found love with the Red needle. You very rarely see them both work well.

Awesome, thanks for the input Jake :cool: I'm going to get one of the N3EG needles and start there; will probably also get one of the NEDG needles to have on hand.

To verify, a quick web search for N3EG gives a Yamaha p/n of 4SR-14916-EG-00 - sound like the one I'm after? And the NEDG needle is a Zuk RM of p/n 13383-37FJ0; sound right?

I'll also throw a thread up in the WTB section on the JD blue...never know :D

If you want to go ktm way----54731134000 ktm jet needle keihin n3eg.

Before you try to tame it down put a few rides on it and see where he lands.
But if it isnt rideable here is some of what you can do in order.
Flywheel weight.
Different silencer.
Higher gearing.
Spacer on the intake.
Richer jetting.

There is more you can do but I would start there.

Cool, good ideas. Richer jetting and gearing will be easy to try. I need to check the gearing; don't remember what it is off the top of my head. I'm looking forward to trying the N3EG needles and see what that does.

Brad,

My brother has an '03 ec250 and he has it jetted to perfection. It was a long process of trial and error, but it is so linear and crisp. Very easy to ride with the low end that feels like a 300 and the crisp response when needed.

He, of course, has RB head mod and is running: 40 pilot, 170 main, #7 slide, CCK #2.

BTW, you planning on riding the ec250? Love to hear your impressions if you do.

Hey Russ -

That's quite a bit leaner on the MJ than this came with, might look into going leaner if she feels fat up top (think I have a 175 MJ in my collection). I ordered the Yamaha needle (N3EG) and I'm going to throw that in this weekend to test. If it doesn't feel that good, I'll tell my brother-in-law to order the CCK. The bike hasn't had the head mod yet - that'll probably happen when I'm able to walk him through what needs to be done.

I'm sure I'll take a few spins on the 250 when we do the Tee Pee run at McCubbins the last weekend of May. Are you going? Anyway, my first impression on riding it up and down our gravel road is HOLY CARP - the thing has a crazy hit that launches the front wheel skyward through the first 3 gears. I mean, it's an insane hit that's pretty tough to control. I'm hoping the different needle will help smooth the transition and make it manageable - he's likely to put himself into a tree given how hard she hits. I'll be curious to see how she handles the trails, doesn't feel quite as nimble as my 200 - though I did notice the suspension was set pretty stiff, so that needs to be softened.

When my brother and I first got our ec250's I thought I had made made a big mistake. It was one of the most intimidating bikes I had ridden! The jetting was so aggressive that you spent the entire ride reigning the bike in or riding a least a gear high if not 2.

So, the jetting process began and eventually I sold it with the jetting better, but not great. My brother kept his and now has it perfect. I must say it is so easy to ride. Smooth linear delivery and very controllable. It's a bike you can ride all day now. Very enjoyable.


Yes, I'm taking 2 of my boys up for the fun run on Saturday of the teepee. I have to work on Sunday. We'll have to hook up.