EC250R 2012 high RPM issue

[blamir]

Hello gassers,

My jets was like this,

178 Main Jet
42 iddle jet
N1EF needle #2 from top
Mixture screw 3 turns out.
Sea level

Bike was working abit rich. i had a problem on high rews. Bike was not going up high rpms. So i changed the jets like this,

MJ: 172
IJ: 32
N1EF needle #2 from top
Air screw: 1 and half turns out
Wheather: 28C
Sea Level

Throttle response is perfect. It is not passing on top revs. It is more agressive . Medium rpms is really good. But low rpms are abit week. At 1st gear, bike is not revving high as in the past. It is suddenly accalareting after low rpms .

I see that no one use N1EF needle, is this so bad? I really wonder other needle settings but it is not easy to find any another needle in Turkey.

What is your offers for better jetting? What is the best N1EF combination?
Is there any online sites to order needles with cheap international shipping option?

With new plug, after 20 min riding, with new settings. MJ: 172, IJ: 32, N1EF needle #2 from top

Thanks

 

[Jim Cook]

Hello gassers,

My jets was like this,

178 Main Jet
42 iddle jet
N1EF needle #2 from top
Mixture screw 3 turns out.
Sea level

Bike was working abit rich. i had a problem on high rews. Bike was not going up high rpms. So i changed the jets like this,

MJ: 172
IJ: 32
N1EF needle #2 from top
Air screw: 1 and half turns out
Wheather: 28C
Sea Level

Throttle response is perfect. It is not passing on top revs. It is more agressive . Medium rpms is really good. But low rpms are abit week. At 1st gear, bike is not revving high as in the past. It is suddenly accalareting after low rpms .

I see that no one use N1EF needle, is this so bad? I really wonder other needle settings but it is not easy to find any another needle in Turkey.

What is your offers for better jetting? What is the best N1EF combination?
Is there any online sites to order needles with cheap international shipping option?

With new plug, after 20 min riding, with new settings. MJ: 172, IJ: 32, N1EF needle #2 from top

Thanks

I normally ride from sea level to 1,000 meters elevation. I jet accordingly.

The N1E* series of jet needles are really Kawasaki MX series needles from the '90s. They would work well for racing, but the jetting was not really "clean" down low and did not give a really smooth transition from low rpm to the midrange. Also, to get the engines to idle, one often had to turn in the throttle stop screw all the way, which had the effect of moving you up and out of the actual idle circuit.
That is why the LT Racing jet needles were so popular. Les helped a lot of people clean up their carburetion with his jet kits.

With the older model AS1 carburetor, the only N1E* series jet needle that I liked and used was the N1EG needle with the clip in the second groove from the top, coupled with a 42 pilot jet and a 175 or 178 main jet. (The main jet selection depended on intended use, hare scramble or trail riding/working, and ambient temperature).

The AS2 carburetor on my 2011 EC250 demands much leaner jetting. (An observation, as I tried my former jetting before I tried anything else, with unsatisfactory results.)
After reading the jetting threads on this forum, and talking with others who had already been experimenting with the jetting on their AS2 carburetors, I started trying various YZ250 and RM250 jet needles.

I tried several jet needles, and gradually went leaner and leaner, cleaning up power (and lowering the amount of black exhaust spooge being blown out the end of the silencer) as I did my testing.

Right now, I have achieved a very smooth, but strong, setup using an optional jet needle for the 2006 Suzuki RM250, the NEDJ, with the clip in the second groove from the top. To go with it, I am running a 42 pilot jet and a 175 main jet. These settings wo;; ;et tje emgome od;e as O taple arrows to trees and pull them down after the races.
It is still spooging out the silencer just a bit during trail work and slow/easy trail riding and trail working, so I am probably going to try the 40 pilot jet, and then after getting some results for comparison purposes, a 172 main jet. (Since it's summer and averages over 90F here in south Arkansas, USA, unless I race a hare scramble, I probably don't need the 175 main jet to protect the engine.)
From the www.rockymountainatv.com web site, you can see the parts breakdown and parts list.
It states part "#13383-37FM0 NEEDLE, JET (NEDJ)".

I couldn't find parts diagrams on the Suzuki web site, but you can look here to get started to see the breakdown and parts list:
http://www.rockymountainatvmc.com/oem-schematic/3

One more thing: I don't put much faith into reading the plug on a 2-stroke, unless it is to see if the main jet is dangerously lean. On a 2-stroke, the plug is going to give you a reading on whichever throttle setting you were using before you killed the engine.
I put much more stock in "seat of the pants" feeling and the exhaust sound while riding the same section of trail over and over.

Good luck to you on your quest for the best jetting, and
Good Riding to You!
Jim



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[blamir]

Hey Jim thank you for explanation. I ordered two needles . It takes 2 weeks to get order. Till then i am going to ride with new settings.

In your opinion, is this too lean? MJ172 Idle32 and clip position 2? Maybe change the clip position to 3 or iddle to 42? This is my first two stroke bike and you guys have the best experience with the two strokes.

Your comments are so valuable for me.

 

[Jakobi]

The high racing idle is because a 32 pilot is too lean for a 250, and the idle screw will be wound in too far to compensate for the rich condition the needle is causing. Basically you will have lifted the slide a lot with the idle screw to the extent that the needle is actually sitting on the first taper at idle. It then makes it very inconsistant and the air screw will have little effect.

For most the needles you read about they can be ordered through OEM dealerships respectively. Suzuki/Ktm/Yamaha.

In my 2013 EC250R I settled on 40 NEDW#2 175

 

[blamir]

The high racing idle is because a 32 pilot is too lean for a 250, and the idle screw will be wound in too far to compensate for the rich condition the needle is causing. Basically you will have lifted the slide a lot with the idle screw to the extent that the needle is actually sitting on the first taper at idle. It then makes it very inconsistant and the air screw will have little effect.

For most the needles you read about they can be ordered through OEM dealerships respectively. Suzuki/Ktm/Yamaha.

In my 2013 EC250R I settled on 40 NEDW#2 175

Are the all jets the same for Keihin PWKS 38 carburetor from other brands? I will buy a 40 iddle from KTM.

 

[Jim Cook]

Are the all jets the same for Keihin PWKS 38 carburetor from other brands? I will buy a 40 iddle from KTM.

Yes. All Keihin PWK carburetors use the same series main jets, pilot jets, and jet needles, regardless of the size.

Jakobi answered your other question very well. His choice of jet needle is "one" richer than my choice of the NEDJ (if I figured the listings correctly). I think the power is just a bit more "snappy" with the NEDJ and a bit "smoother" with the NEDW. I see that he is running the 40 pilot jet that I am planning on giving a try.

Let us know how it goes for you.


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[Jakobi]

I've had some work done to my head which is why it prefers a touch more on the diameter. I could probably run a 42/J diameter too. Its really splitting straws and fine tuning the closed to 1/8th throttle range here.

Both needles run the same clip for clip once off the straight section.

 

[desertgasser300]

Agreed that 32P sounds really lean. I run at 1100' above sea level and I run a 42 in winter and a 40 in summer. I will go as lean as a 38 when I go to Colorado and a 168 main.

 

[blamir]

Hello guys,

Today i changed iddle with 32 to 38, could not find 40. It is much better than 32. Air mixture still open 1 and half turnout.

Tried full throttle and i see plug could not ignition after 3 seconds on top rev. My bike was not geting top revs before. It takes top revs right now but started passing ingition after a few seconds.
It makes only at 1st gear not 2 or 3rd.

This is not problem for me. I am not going with full throttle all time. I wonder is this normal response.

Edit: Today KTM dealer said me that, gasgas 2t engine is honda cr250 engine so it's fuel consiption is so high. Is that true? and yz and cr needles is not suitable for gasgas. Anyway i ordered the needles. My bike come back to life with your offers.

 

[desertgasser300]

Hello guys,

Today i changed iddle with 32 to 38, could not find 40. It is much better than 32. Air mixture still open 1 and half turnout.

Tried full throttle and i see plug could not ignition after 3 seconds on top rev. My bike was not geting top revs before. It takes top revs right now but started passing ingition after a few seconds.
It makes only at 1st gear not 2 or 3rd.

This is not problem for me. I am not going with full throttle all time. I wonder is this normal response.

Edit: Today KTM dealer said me that, gasgas 2t engine is honda cr250 engine so it's fuel consiption is so high. Is that true? and yz and cr needles is not suitable for gasgas. Anyway i ordered the needles. My bike come back to life with your offers.

Go tell that KTM dealer he is full of sh!t! He wants you to buy a KTM.

 

[Jim Cook]

Hello guys,

Today i changed iddle with 32 to 38, could not find 40. It is much better than 32. Air mixture still open 1 and half turnout.

Tried full throttle and i see plug could not ignition after 3 seconds on top rev. My bike was not geting top revs before. It takes top revs right now but started passing ingition after a few seconds.
It makes only at 1st gear not 2 or 3rd.

This is not problem for me. I am not going with full throttle all time. I wonder is this normal response.

Edit: Today KTM dealer said me that, gasgas 2t engine is honda cr250 engine so it's fuel consiption is so high. Is that true? and yz and cr needles is not suitable for gasgas. Anyway i ordered the needles. My bike come back to life with your offers.

Don't listen to the KTM dealer. He obviously has not done his homework.
For full throttle runs (down a long straight or a road for longer than 8 seconds), you are going to need at least the 175 main jet to protect your engine; and for sustained full throttle runs, you can probably use a 178 main jet.

The GasGas engine was originally designed by combining aspects of the CR250 and the TM250 engines. Then, they refined the porting and powervavle specifications to give the power delivery that they desired. I like being able to use a CR250 connecting rod kit and piston kit. We have bored the 250 cylinder 3mm to 69.5mm (also recoated the cylinder bore with nikasil and built up the head to match the cylinder bore) so that we could run the 14th oversize Wiseco piston for a Honda TRX250R racing quad. This also made necessary the "shaving" of the powervalve "flapper". It gave us a 274cc displacement. I ran one for 5 years on a '98 counterbalanced engine. It was great. It had more torque than the 250cc, but still felt like a 250 instead of a 300 as I raced between the trees in tight woods trails.


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[blamir]

178MJ fouls plug after 2 or 3 riding. N1EF needle a bit rich. 172 looks fine with this needle. Tomorrow i am going to post a video from Istanbul forests

Cheers

 

[Jakobi]

The main won't cause the plug to fowl over time. A rich main will just break up and burble when opening WOT.

The issue with the stock setup is the needle diameter and rich first taper. Everything else you do to try and work around and resolve this is just a bandaid (smaller pilot, raising clip position, smaller mains). They may improve the small throttle loading, but as you have experienced already, cause other issues elsewhere.

 

[blamir]

Hello guys,

Today i rode gasgassss and i can say that it is more agressive than old settings. I failed two times stupidly. Power is not rising balenced. Bike gets away under my ass suddenly . Pipe was not oiled much as before. I liked it.

I am waiting for suzuki and yamaha needle. i wonder how they will change ride capability.

Here is gasgas fail What is my mistake .
http://www.youtube.com/watch?v=xhlnWa-6Uk8

 

[gasmonkey]

You fail cause you ride like old lady.N1EF sounds like crap.Put suzuki needle soon as possible in and change of ride capability will go up.

 

[desertgasser300]

My 300 loves the JD red needle. My 250 likes the JD blue. Setting the float height was key to getting both bikes tuned properly.

 

[Jim Cook]

178MJ fouls plug after 2 or 3 riding. N1EF needle a bit rich. 172 looks fine with this needle. Tomorrow i am going to post a video from Istanbul forests

Cheers

Was that the video you promised? Where are the trees?

It will get better when you put one of the new jet needles in.
When climbing hills, remember, "Momentum is your friend."

Good Riding and thanks for the video.
Jim



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[Elvis74]

By the way, KTM has a 36mm and GasGas a 38mm carb. That's one reason for the different jetting between the brands.

 

[Jim Cook]

By the way, KTM has a 36mm and GasGas a 38mm carb. That's one reason for the different jetting between the brands.

Speaking of this:
Once at the shop, a friend brought in a '99 GasGas he had bought for me to fix his "throttle sticking" problem.

The previous owner had iinstalled a KTM jet needle, which was too short. When I "whacked open" the throttle firmly, the needle could come out of the needle jet and stick, and the bike would be stuck on "WFO".

If anyone uses a KTM spec needle, make sure it's long enough to not cause this problem.

 

[blamir]

Was that the video you promised? Where are the trees?

It will get better when you put one of the new jet needles in.
When climbing hills, remember, "Momentum is your friend."

Good Riding and thanks for the video.
Jim



.

Hello Jim,

I had some problem with video encoding. I am adding a video.

It was a slow ride
http://www.youtube.com/watch?v=0xBMoWex1NY

Edit: What is the size of BOTTOM STEERING NUT?