Factory Needle/Jet Setting EC250

[theexception_03]

Hi tim,
i would be a little careful about following what others are using in different countrys too, lots of different fuels, this will change jetting alot.
you have plenty of needles to play with to get your bike going well, follow the process as described by jakobi, (thanks for that by the way, cleared a few questions in my head.) and you will work out what is best for your bike...
and if you want, for comparison, as im just over in central victoria, riding similar altitudes, temps and weather, and fuel...
09 250r (with the older scew top carb)
40pj although im going to try a 42 yet.
NEDW 2nd clip
178 main
7 slide.
air screw is at the moment on about 1 turn but i keep playing with it and hence my wish to try a 42pj..
i cant say its perfect, but its bloody close...

dont worry about your cdi or anything yet, try your jetting first...
good luck.

Great to here from someone close to home and with a similar set up, I am getting a bit worried on if I will ever have clean crisp running bike. So many variables, jetting, CDI, Reed valves, spark plug, fuel etc etc.

I will stick to trying different jetting before I move on to anything else.
Just as a matter of interest are you using the BR8EG plug and 50:1 fuel/oil ratio?

 

[Jakobi]

Great to here from someone close to home and with a similar set up, I am getting a bit worried on if I will ever have clean crisp running bike. So many variables, jetting, CDI, Reed valves, spark plug, fuel etc etc.

I will stick to trying different jetting before I move on to anything else.
Just as a matter of interest are you using the BR8EG plug and 50:1 fuel/oil ratio?

Work through the list in a sequential order. No amount of jetting will fix a mechanical issue.

Compression test (may or may not tell you too much, usually better for gauging wear from a reading off a fresh piston).

Pull the carb out - remove all the jets. Soak them in carb cleaner and blow out with compressed air. Clean up the carb in and out and make sure no obstructions. Confirm and set the float height with the carb out of the bike.

While the carb is out - pull the reed block and check the petals for wear. While this is out you can get a visual on the rear of the piston at bdc.

Pull the pipe - Have it cleaned if it looks crusted up. Repack the silencer if it hasn't been done in some time. Visually inspect the front of the piston from the exhaust port. Inspect PV assembly for gumming/carbon deposits while there.

Depending on what you find, take pics, post them, seek opinions, and replace what needs to be replaced. Reassemble, throw a fresh plug in BR8EG/BR8ES, fresh fuel at 50:1 with a quality oil. Amsoil is highly regarded but can be a bit pricey and hard to find in Aus. I was fond of the GRO Synth 7, prior to getting amsoil.

Then, take one of the jetting specs I listed and work with it methodically one circuit at a time. You'll get great results, but you'll never jet out a mechanical issue, and with electrical you can chase your tail replacing parts. If you have a doner bike to swap some parts out with it can help, otherwise reading and multi meter is the go.

 

[theexception_03]

Got the 250 to idle

Latest results from this setting

DDK #3
45 pj
180 mj
A/S 1.5

Got it to idle really well, no problems

I took it for a 5 min test ride and she pulled really hard from idle to 1/4 throttle
but started to burble or 'miss' once the revs were getting into the high end of the mid range at half throttle

I have attached 2 pics of the plug after this very short test ride, running lean now, so I am wondering... do I change clip positions or go up in the main jet?

Cheers
Tim

 

[Jakobi]

Burble/Miss? Different things.. Best way to know the circuit you're working with is to index the throttle. Mark it out at 0, 1/4, 1/2, 3/4 and WOT so you can visually check and be sure what throttle opening its at.

Burble/breaking up is usually a rich condition. Hesitating/missing is generally a lean condition. 1/4 - 1/2 throttle is the needle clip position.

If that was a new plug you're not going to have much luck reading it like that. To read a new plug you need to cut the thread back and read the fuel ring at the base. I use an old coloured plug to test using the upper electrode as if its lean enough it will turn the old colour white/grey.

I'm still going to reiterate what I said before about trying to jet a mechanical issue. You can chase your tail forever otherwise.

 

[theexception_03]

Here is my Reed valve, not sure if its in good condition or needs attention.

 

[Jakobi]

Hold it up to the light and look through it from the intake side. It should be sealed shut. Hard to tell if there is any fraying on the edges from the photos but in general looking ok. Definately not too bad.

 

[lonetree]

see how its lifting up a bit? the smaller flap....
not supposed to... they should be flush and seal, its a one way valve so to speak....
on my old 04 i just flipped the reeds over so they sealed again, probably not the best, but if there is not chips or anything, as mine were, it seems to work ok.

 

[pscook]

Look at it in profile for gaps between the outer and inner reeds. Here's what I did to test my reed's sealing capacity, see if it works for you. It didn't make much difference to me, but there was a host of other potential issues that I wanted to resolve concurrently with the reeds and jetting.

http://www.gasgasrider.org/forum/showpost.php?p=76462&postcount=14

 

[Jakobi]

I'd flip em like Lonetree said. The other post gives a good visual on how they should look and shouldn't. You wouldn't expect that to be enough to cause any major running issues, but as stated, one less variable to work with.

 

[pscook]

One thing to note when flipping the reeds, there was a step at the base. That made them unidirectional, as in they only fit one way. I tried to flip mine, but the ridge/step at the end made it fit very poorly, hence the rubber band "shim" approach. Just something to watch for.

 

[GMP]

Why screw around? Just replace them if they look questionable. Is the glass resin surface sticky? You don't have to get the old GG RAD valve reeds, they are the same as a Honda CR250 RAD valve from Boyesen. You should have the choice between fiberglass like OEM or Carbon Fiber as well.

 

[theexception_03]

Reed Valves, I just flipped one side, the petals are now flush, didn't make any difference to the performance.

Anyway I have got the bike to idle, seems to like the 45 pilot, A/S 2 turns out.

The 'miss' that keeps happening is like a rev limiter. This happens with the same needle running different MJ's that i currently have. (175, 178, 180, 185)

I have noticed that at Idle the head light is very dull, as soon as i rev the engine the lights go brighter, I have a feeling this shouldn't happen.

So this is where I am at, Carby is clean, float level good, has new fuel inlet valve. Got new crank oil seal, with all new gaskets on the RHS. I have 2 spark plugs that have the correct gap with very little use, power valve working ok, new air filter, removed throttle cable and re routed it to stop the issue of the idle changing when turning the bars.


I think I will be taking it to the shop, I have tried my best and thanks for all the advice on jetting, I have learned alot.

 

[Jakobi]

Reed Valves, I just flipped one side, the petals are now flush, didn't make any difference to the performance.

Anyway I have got the bike to idle, seems to like the 45 pilot, A/S 2 turns out.

The 'miss' that keeps happening is like a rev limiter. This happens with the same needle running different MJ's that i currently have. (175, 178, 180, 185)

I have noticed that at Idle the head light is very dull, as soon as i rev the engine the lights go brighter, I have a feeling this shouldn't happen.

So this is where I am at, Carby is clean, float level good, has new fuel inlet valve. Got new crank oil seal, with all new gaskets on the RHS. I have 2 spark plugs that have the correct gap with very little use, power valve working ok, new air filter, removed throttle cable and re routed it to stop the issue of the idle changing when turning the bars.


I think I will be taking it to the shop, I have tried my best and thanks for all the advice on jetting, I have learned alot.

I think I may have mentioned this before.. But..

If the stumble is between 1/4 throttle and 1/2 throttle and then the crircuit to look at is the needle clip position. Don't give up on yourself yet. If the bike is making a noise like bla bla bla bla bla then its probably a rich condition which sounds more appropriate as its hard to rev through a really rich condition where a lean will either cut out and then take off or just cut out. Think sounds like either boooowaaaahh or booooooooo*stalls*.

From the info you've provided I'd suggest raising the clip 1 position towards the top of the needle and trying again.

Also the stator action is completely normal considering the bike doesn't run a battery so all power for the light comes from the stator. Low revs, lower power being produced, less light. As the revs climb so does the electrical output and if you've ever had a regulator/rectifier pack it in, thats why the bike starts blowing light bulbs. Its feeding too much power to the light. Nothing to stress about in your case

Waiting to hear the next update!

 

[theexception_03]

Ok, I won't give up.....yet.

I tried this today

N3EW #3
PJ 45
MJ 178
A/S 2

I marked the throttle postions as instructed

Idle good
0 - 1/4 'missing'
1/4 - 1/2 strong in all gears except 1st (I think it just goes to fast thru the rev range in first)
1/2 - WOT is ok but seems to hit red line really quick

I have a feeling that I need to drop down a size in the pilot.

Getting closer now.

FYI, I have a mates 2006 KTM300exc at my place, I kicked it over just to feel the difference between it and the gas gas. The gas gas feels so much crisper and stronger, the KTM seems to feel sluggish to rev up and takes its time getting back to idle once the throttle is closed.

 

[lonetree]

yep. pilot looks to be too big... try 42, then maybe a 40....
you'll get there.... keep tryin....

 

[GMP]

Missing how? Blubbering or bogging? It idles good, but do you have the idle screw cranked in far to do it? If it idles good on the pilot ckt without cranking in the screw, that tells me the pilot is good or very close and the "missing" is from the needle. That may be a lean dia. needle for an older 250 with an AS I carb. I've jetted a few 250s and also a Husky WR250 with an AS I conversion, and all prefered a much richer straight section on the needle than a "W" dia. for best off idle torque.

Evaluate jetting under a load, not unloaded in a low gear. Find a safe place with a slight incline.

 

[theexception_03]

Missing how? Blubbering or bogging? It idles good, but do you have the idle screw cranked in far to do it? If it idles good on the pilot ckt without cranking in the screw, that tells me the pilot is good or very close and the "missing" is from the needle. That may be a lean dia. needle for an older 250 with an AS I carb. I've jetted a few 250s and also a Husky WR250 with an AS I conversion, and all prefered a much richer straight section on the needle than a "W" dia. for best off idle torque.

Evaluate jetting under a load, not unloaded in a low gear. Find a safe place with a slight incline.

Blubbering sounds like the word that describes what is happening. but once I open up to 1/2 throttle and the revs start to pick up it feels awesome but very hard to ride at lower revs at 1/4 throttle.
Here are the needles I have NEDW, NECW, N3EW, DDK, N1EC, N1EF...

I can't seem to find a JD Blue without buying the entire jetting kit.

 

[gasmonkey]

As said before,your nearly there.Drop the pilot a size or two then go to clip 2.Remember,one thing at a time.

 

[Jakobi]

As said before,your nearly there.Drop the pilot a size or two then go to clip 2.Remember,one thing at a time.

Sound advice here!

If you really want to embrace the effect of the pilot circuit open that air screw up some more. Come out a good 3 -3.5 turns just riding around the yard and feel the difference. Then turn it back in to 1/2 a turn out and ride again. I'd be dropping to a 42 or 40 pilot, and then if still not cleaning up raising the clip 1 position.

 

[theexception_03]

Missing how? Blubbering or bogging? It idles good, but do you have the idle screw cranked in far to do it? If it idles good on the pilot ckt without cranking in the screw, that tells me the pilot is good or very close and the "missing" is from the needle. That may be a lean dia. needle for an older 250 with an AS I carb. I've jetted a few 250s and also a Husky WR250 with an AS I conversion, and all prefered a much richer straight section on the needle than a "W" dia. for best off idle torque.

Evaluate jetting under a load, not unloaded in a low gear. Find a safe place with a slight incline.

The idle screw is only about 1 turn out, so yes its in alot.