Jetting ?

[Diggs345]

I was just curious about the red needle as i had it in my jetting box not in the bike , i need to look atmy jetting but its ridable as is , problem where i live is there is nowhere i can take it to spend a couple of hours to dial it in .
I have lifted the needle a clip as it seemed to be flat in the bottom half of the power and not as torqey as my 09 bike .

 

[GMP]

Thats exactly how mine felt. Flat means lean. What slide do you have, a #7 with a notch or no notch? I just discovered mine in notched which explains its desire for richer needle settings than my '07.

 

[Jakobi]

Maybe thats why I'm consistanly digging the leaner diameters. #7 and non notched here, mixed in with tropical conditions, high temps, high humidity, and a good couple hundred meters of altitude.

 

[Diggs345]

its got a number 7 slide , i need to clean my bike before i check to see if it has a notch.
when i was racing at the weekend i was having big problems in the midrange , i was having to use the clutch a lot to gtet into the power , but then i had too much power .
i called to order a NEDJ and out carb guy in the uk said that means nothing to him , said i need 3 letters only , anyone help me out

 

[Jakobi]

its got a number 7 slide , i need to clean my bike before i check to see if it has a notch.
when i was racing at the weekend i was having big problems in the midrange , i was having to use the clutch a lot to gtet into the power , but then i had too much power .
i called to order a NEDJ and out carb guy in the uk said that means nothing to him , said i need 3 letters only , anyone help me out

Yep! Call a suzuki dealer and ask for NEDJ from a 2007 RM250 - Part: 13383-37FM0

 

[Diggs345]

Yep! Call a suzuki dealer and ask for NEDJ from a 2007 RM250 - Part: 13383-37FM0

will that be a good needle for my bike jake

 

[Jakobi]

Its worked well for others. Should give a very linear clean power with no abrupt hits. Should only set you back around $12usd.

 

[Diggs345]

Its worked well for others. Should give a very linear clean power with no abrupt hits. Should only set you back around $12usd.

thanks thats what im after , that will be about ?30 here then

 

[Diggs345]

Out of stock at all the dealers , do you know the keihin code for that needle or the taper sizes

 

[GMP]

Try working with a CCK/CEK if you have trouble getting the OEM needles. They are half the price as well. Should get you close and be fine until you can get the others to experiment with. Your lean for sure through the mid, then the bike gets fuel from the main and explodes.

 

[Diggs345]

Thanks Glenn , they are on their way .
I thought the bike was rich in the mia as was like running with the choke on

 

[rootsnrocks]

Ended up getting the JD Jet Kit and ran the Blue needle, kept the 180 main, 38 Pilot and clip in 3rd position. Seemed to run good and finally would open up and scream when at WOT. Air screw 1.5 turns.

Looking to make some changes to winter jetting but don't have much time to test before an upcoming cold weather enduro. I am going to run 185 main, 42 pilot, and air screw at 0.5 turns.

I think this should be on the safe side (plenty rich).

The bike ate a ring when I was on the pipe in the sand at 30-40F with the jetting listed above. The piston/rings needed to be changed, but I am wondering if it was too lean and got hot. Nothing was melted but the heat could been a catalyst for the failure...

Thoughts?

 

[Jakobi]

Depends how it ate the ring. If they were just out of spec and snagged in a port I'd say it has very little to do with the jetting you were running. The piston dome should tell some of the story too!

 

[rootsnrocks]

Yes I am sure it could-I will post a pic.. It definitely snagged on the exhaust port. It needed a rebuild pretty bad it was my last ride before I was going to tear it down-lesson learned, cost me an extra $250 to have the cylinder repaired and re-plated.I think the underside of the piston could also be telling i.e. piston-wash. I will post some pics.

In any case there must be a reason people change jetting in the winter. Obviously it will run better with the proper jetting but isn't also risky to run summer jetting in the cold weather?

 

[GMP]

I run a richer pilot in late fall, early spring, all else same. One up on main if its real cold. I run the same as you but a 42 - 45 pilot in my '07 and 45 - 48 in my '12 (notched slide). Last HS race was in the high 30s with a lot of fast stuff and the bike ran awesome, not lean. I think you went bang because you were overdue on maintanence, not jetting. Try going up on your pilot, it would not surprise me if you picked up some low end torque. I'd probably go up on the main if I was doing a lot of WFO sand stuff, regardless of temp.

 

[rootsnrocks]

Okay thanks for the help. I went up to a 42 pilot and I thought I had a 182 main kicking around from the JD kit (the biggest they supplied was a 180 the others were 178, 175, 172??) but turns out I didn't so I raised the needle one clip, also turned the air-screw in a bit and it idles nice now.

I keep hearing that you should adjust your air-screw until you get a good idle. What is the idle screw for then? How do you know when to adjust either screw?

 

[Jakobi]

The idle screw is basically just a throttle stop. It holds the slide open, as does your hand when its on the throttle a little.

The air screw actually meteres the mixture at idle and works best between 1 and 2.5 turns out from fully seated.

So relative to eachother, the pilot jet, needle diameter, air screw, and slide cutaway all work together to maintain your idle and off idle response. You can use the idle screw to lift the slide up allowing more air in to account for rich conditions to a certain extent, but if going too far in you lift the slide so high that you effectively bypass the straight section of the needle and the air screw will have very little effect at all. You'll probably get intermittent idling too where in one case it will idle and start well, yet another day it'll flame out a lot and be hard to start.

 

[theexception_03]

OK, I'm in NJ, and have jetted several of my 250s with AS1 carbs, including my new '12. First make sure the bike is sound. Good reeds, seals, PV opening correctly, compression, etc. Float level is correct. Slide should be #7, if by chance it is not, get one, a #6 will make things difficult. Next, forget about spooge, especially if you run a spark arrestor and double that if its a Stealth spooge trap. We jet the 250 by feel for torque, period. They like to be on the rich side for max torque, and WILL spooge. Also, much of the information here is relative to the newer AS2 carbs that tend to prefer much leaner jetting. IMO, the NEDW will be too lean, so don't rush out and order one. My experience with needles of the same straight diameter tell me this. Even the CCK is borderline in some 250s, and from my experience the AS1 equipped 250s prefer the richer D taper needles like a DDK or DEK. For the main, 180 should not be too rich with a fat tip needle like these. You could be flat on top from being slightly lean, not rich. I have gone as high as a 185 main and still had good top end. The best needle I have found for the 250 for our conditions is the JD Blue. Expensive kit but it really works well and makes great power throughout the range. You can start with a DDK and DEK (one half clip range apart) and get it very close.

Try this:
45 pilot
DDK #3
182 main
air screw 1.5 turns

DEK #3 is a half clip leaner, DEK #4 a half clip richer for fine tuning.
Go up on the main until it obviously rich and back down two sizes and you should be there. If you can get it pretty good like this, the JD Blue will drop in in clip #3 or #4 and it will be perfect.

Just reading your advice and would like to know about my set up.
2005 EC250
running at sea level @ 25'C (77'F)
fuel 50:1
DEP pipe

DDK#2
180 main
45 pilot
air screw 2.5 turns

it feels like a really good set up when I ride it, good from down low and right thru the rev range to WOT

but

it doesn't like to idle, I have the idle screw nearly all the way in

any suggestions?

(all other parts like PV, reeds, spark, CDI and stator are all great)

 

[gg3]

2010 ec300 38mm carb.
sea level to 500m.21 to 28 degrees
Main-180. P-40 4 turns out. Needle JD Blue clip2.
Real happy with this.Excellent torque & screaming top,nice transition.
Weird thing is I changed to a 38 pilot & tried it at .5,1,2,3 turns out & couldn't get it as good as the 40 at 4 turns.Theory says 4 out is wrong but it loves it!