2011 ec250 jetting ?????

[dinobody]

Just got a 2011 Ec250 trying to figure out where the carb should be.
Ok I looked thru the jetting fourm but didnt come up with anything.
Here is what is in it now.
The needle is an n8rh 4 grooves down
162 main
35 idle
I live at 7400ft.and ride from 5500ft. to 9000ft. or so.
S.W. Colorado Durango

Any help would be great!!
Thanks
Doug

 

[Jakobi]

Just got a 2011 Ec250 trying to figure out where the carb should be.
Ok I looked thru the jetting fourm but didnt come up with anything.
Here is what is in it now.
The needle is an n8rh 4 grooves down
162 main
35 idle
I live at 7400ft.and ride from 5500ft. to 9000ft. or so.
S.W. Colorado Durango

Any help would be great!!
Thanks
Doug

How does the bike run now? What are you looking to change.

First impressions looking at what you're running is.. Way small on the pilot.. Way rich on the needle.. I can't judge the main, but looks small for a 250 too.

I see you are at altitude which would mean you'd typically want to lean things out across the board, however the needle and clip you are running are really rich. Much richer than the stock needle (which many people at slight elevation find too rich).

At a guess I'd say your bike probably runs like a real pig from 1/8th - 1/4 throttle before things start to clear out into the top end. Really pulling well from 1/2 to WOT. I think the small pilot is a band aid to try and help clean up the rich taper and clip pos of the needle.

 

[Jakobi]

And something I just posted in another thread thats relevant to you..

Confirmed in Yamaha Manual
N8RH (Rich)
N3EH
N8RW
N3EW (Stock)
N3CW
N3EJ
N3CJ (Lean)

So judging from that I already know that N3C is half a clip leaner than N3E, so N8R will be half a clip richer. The last letter is the diameter richest to leanest H, W, J. FWW I've been running the N3CJ#2 in my 300.

 

[kaos]

i went and bought a few of the needles and jets mentioned here and tried them out with some ok results,but ended up with the jd jetting kit.it works perfect at all the aspects- starting -idle-bottom -mid and top.(granted its the needle that is making the diff,but the jd red outperformes all the others i tried

 

[twowheels]

Just got a 2011 Ec250 trying to figure out where the carb should be.
Ok I looked thru the jetting fourm but didnt come up with anything.
Here is what is in it now.
The needle is an n8rh 4 grooves down
162 main
35 idle
I live at 7400ft.and ride from 5500ft. to 9000ft. or so.
S.W. Colorado Durango

Any help would be great!!
Thanks
Doug

Did you identify if this was a 36 or 38mm carb?

 

[dinobody]

How does the bike run now? What are you looking to change.

First impressions looking at what you're running is.. Way small on the pilot.. Way rich on the needle.. I can't judge the main, but looks small for a 250 too.

I see you are at altitude which would mean you'd typically want to lean things out across the board, however the needle and clip you are running are really rich. Much richer than the stock needle (which many people at slight elevation find too rich).

At a guess I'd say your bike probably runs like a real pig from 1/8th - 1/4 throttle before things start to clear out into the top end. Really pulling well from 1/2 to WOT. I think the small pilot is a band aid to try and help clean up the rich taper and clip pos of the needle.

The bike runs more like a goat almost pig like. Good guess!!! from 1/8 -1/4 throttle. Pretty good after that. So the bike came with a bag of jets and a needle. The needle is a CHN where does that fall? The plug dosent look to bad a little wet. Also running 50 to 1 With Motule syn oil I think it is the 800. I think the carb is a 38mm that is what is supposed to be from the factory. How do you tell?

 

[Jakobi]

The bike runs more like a goat almost pig like. Good guess!!! from 1/8 -1/4 throttle. Pretty good after that. So the bike came with a bag of jets and a needle. The needle is a CHN where does that fall? The plug dosent look to bad a little wet. Also running 50 to 1 With Motule syn oil I think it is the 800. I think the carb is a 38mm that is what is supposed to be from the factory. How do you tell?

The CHN needle that comes with the bike is what they use in the restricted models (closed airbox, cat converter in the pipe). Its way too lean to use with a normal setup.

On top of the carb cap you will see a number printed in a circle. 36/38. This is the carb size. Some shipped with the 36's and will make a big difference in your jetting specs.

What temps are you riding in?

I'd personal start at minimum with a 42P and a 172Main to be safe, and then lift the clip on the needle one spot at a time until things clean up and feel crisp. A fat pilot won't idle and will burble on low throttle but should clean up coming into the needle and will be noticable if it needs to go bigger or smaller based on AS adjustements. The fat main will be noticable around WOT. The needle position has the biggest effect at 1/4 throttle.

 

[dinobody]

The CHN needle that comes with the bike is what they use in the restricted models (closed airbox, cat converter in the pipe). Its way too lean to use with a normal setup.

On top of the carb cap you will see a number printed in a circle. 36/38. This is the carb size. Some shipped with the 36's and will make a big difference in your jetting specs.

What temps are you riding in?

I'd personal start at minimum with a 42P and a 172Main to be safe, and then lift the clip on the needle one spot at a time until things clean up and feel crisp. A fat pilot won't idle and will burble on low throttle but should clean up coming into the needle and will be noticable if it needs to go bigger or smaller based on AS adjustements. The fat main will be noticable around WOT. The needle position has the biggest effect at 1/4 throttle.

The carb is a 38mm temps around 70deg. What needle should i get? Will most moto shops carry needles for the keihin carbs? I am a car/truck guy trying to learn motos. Thanks for the help.

 

[Jakobi]

I've never jetted an EC250 but I'd be tempted to use the Yamaha needle N3EW/N3CW and use their jetting chart to get started.

Or.. I'd grab an NEDW/NECW (suzuki needle)

You can order both online and have them delivered or order them through local dealers. Suzi dealer for NEDW/NECW and KTM/Yamaha dealer for N3 needles (they both use and sell them). The N8RH you have may even work well enough for you.

Like I said last post, I'd move the N8RH#3 with a 42 pilot, and 172 main and see how it feels. I'd then move to clip #2 and test again. I think at your alitude you'll probably want to go even leaner again on the needle.

Once the pilot and needle are setup you can start leaning the main out.
I'd be thinking 45 N3CJ#2 168 would be around right at your altitude and temps, but its always best to start rich and work backwards.

 

[MonsterTruck]

Hey Doug,
Fun riding with you yesterday. I think you have some good info here. I don't have much to add. With the summertime temps, and soon even higher elevation, you will end up leaning it out. Mine (300 with 36mm carb) is way leaner than I would ever imagined. It runs super smooth. Just make small, thoughtful, planned out steps and check your plug along the way. BTW, your carb is a 36.
Happy trails.