Hanging idle... pilot? vid

[nokturnal]

2006 EC250 converted to S3 300 cylinder, stock head. No headwork.
180mj, 40pj, 7 slide, JD blue needle, as 1.5 (tho does not matter), idle screw almost all the way in.

It has been displaying the typical erratic idle, must have the slide screw all the way in etc, since it was a 250, low compression and had a DDK needle. Now with the JD kit in the bike will actually idle, eventually, after warming up, and f-ing with the idle screw. Airscrew does almost nothing.

Yesterday I read a thread on float height, so made a cork/tube tool to check the fuel level. Aha! I thought, it was 3 mm above the seam. So I bent the tang until i got it as close as I could, less than 1mm below the seam of the bowl. I though finally this would fix it and my problems chasing the idle were over. Nope... ended up back at the same settings. Same symptoms.

Almost no one at sea level is using a 40 pj, most are at 42 or 45, could I need a 38 even? Will it make that much of a difference and finally get the damn thing to idle? I just seems so unlikely that I would need a pilot that most people would be using in the mountains...

The idle hangs as well. There are no air leaks that I can tell, it has done it ever since I got the bike last year. Throttle cable is fine, and has been replaced recently. When I turn the bars it does nothing. Carb is spotless.

I am sure most will suggest headwork. That is not going to happen anytime soon. The large squish would not cause the hang though would it?

Here is a vid:
http://youtu.be/U0psd5Ezlh0

please excuse my ziptied license plate rattle...

 

[Jakobi]

What does a half a turn in on the air screw do? What does backing off the idle screw a touch do?

I remember chasing tails at one point and being told that these issues can be caused from an excessive squish clearance. It may not be a lean racing hanging idle, and more that some of the fuel charge is being stored under the squish band and then slowly burning off. It could be a load of horse poop too, but my experience was that after setting the squish to appropriate specs everything else fell into place really quickly.

 

[hannesd]

What does a half a turn in on the air screw do? What does backing off the idle screw a touch do?

I remember chasing tails at one point and being told that these issues can be caused from an excessive squish clearance. It may not be a lean racing hanging idle, and more that some of the fuel charge is being stored under the squish band and then slowly burning off. It could be a load of horse poop too, but my experience was that after setting the squish to appropriate specs everything else fell into place really quickly.

i was thinking the exact same thing, need to get my head cut too from the 200, same issue, not that it really matters to me though...
runs nice anyway (yours aswell as mine)

 

[nokturnal]

Airscrew could be 3 turns out or one. No difference really. It could be my imagination, but I feel like when it is further out it bogs a bit more when blipped.

Idle screw must be almost all the way in for it to start from cold. Idles very high on choke ~3-4k, then will drop to around 2k ish when I knock the choke off, after 20sec or so of warm up. Then I will unscrew the idle screw a bit to get it to where it is in the video, so it will drop down to 1k when blipped.

Other than near idle the thing is a beast. Will loft the front in second with only a quick blip.

 

[Jakobi]

If the idle screw is turned all the way in (like bottomed out and spring bound up), then you have essentially bypassed the straight section of the needle, the slide is well and truly open, and the pilot and air screw are getting towards the end of their effect. Thats why adjusting the air screw isn't doing much. Its also why you get inconsistant idles.

Set the squish to improve consistancy and effeciency. Best mod for any 2T.

Set the carb so that the slide is only open, get a needle, and cycle through pilots until you find one that allows the bike to start and idle with the air screw at 1.5 turns out. Remember a cold engine thats well jetted will start on the choke and not off. Thats why its there. If you can take the choke off too soon its too rich. If its cold blooded and won't come up to temp eaily and bogs a lot its too lean.

Slide cutaway, pilot jet, needle diameter - 3 pieces of the puzzle that all need to work in harmony. In my opinion it sounds like your needle/slide is too rich so you have gone with a small pilot to try and crisp up the 1/8th throttle, which has given you some bog and a smaller pilot than you'd expect. You've also had to lift the slide (idle screw) to try and lean the bike out to compensate as well.

Without knowing the model or the slide its documented that #7 works well. If thats what you have then the magic will be in the needle.

 

[GMP]

Did you try a richer pilot or did I miss something? If not try the 45 - 48 pilot. Idle shouldn't hang with that needle, thats actually what I run un the 250s and it runs real well. 40 pilot was always to lean.

 

[nokturnal]

Did you try a richer pilot or did I miss something? If not try the 45 - 48 pilot. Idle shouldn't hang with that needle, thats actually what I run un the 250s and it runs real well. 40 pilot was always to lean.

I originally had a DDK in there and a 45 pilot. Did not try a 42.

I thought that because the idle screw was cranked, that meant that the pilot was rich.

 

[nokturnal]

just to close this down...

42 works perfect. idles and blips fine.

I emailed JD. They gave me the exact setting, and it worked. Thanks guys!

 

[Vindicator]

Airscrew could be 3 turns out or one. No difference really. It could be my imagination, but I feel like when it is further out it bogs a bit more when blipped.

Idle screw must be almost all the way in for it to start from cold. Idles very high on choke ~3-4k, then will drop to around 2k ish when I knock the choke off, after 20sec or so of warm up. Then I will unscrew the idle screw a bit to get it to where it is in the video, so it will drop down to 1k when blipped.

Other than near idle the thing is a beast. Will loft the front in second with only a quick blip.

I have the exact same issue you describe in your post. I found that sometimes the throttle or the slide would get slightly stuck and if I force the throttle to go back it would lower the idle. But this does not happens often, sometimes just in the middle of the ride.
But I definitely can't idle the bike for more than ~1m, it simply stops. I have cleaned the carb more than 10.000 times, changed needles and adjusted the float.
The float adjustment turned out really nice as I was able to lean the engine a little bit, spooge decreased. I don't think running a LeoVince instead of the FMF "spooge trap" (did you guys ever looked at its bowels ?) explains the enormous decrease of spooge itself .

Air screw makes no difference at all if I back it out 2 or 3 turns from full in and bike bogs off idle just like in this Slaven's video http://www.youtube.com/watch?v=zVzqqpgviyI. The air screw not having any effect tells me I should go to lower one but the bog of idle tells me the opposite. The spooge on the pipe when riding technical stuff (lower revs) tells me it's too rich...

At the moment I have:

42 pilot
NOZI #3
180 main
AS 1,5
Slide is 7
38 PWK ASII
Sea level
~15?C

It starts just fine with the choke but if I close it engine stops, I have to compensate with the throttle . When it warms up a bit manages to idle but after a while it shuts down.

I would not like to go with the head mod at this moment especially because it will make the engine to run a tad hotter . I do a lot of technical stuff and I don't want the engine to boyle.
Should I try the 45 pilot?

 

[Jakobi]

I have the exact same issue you describe in your post. I found that sometimes the throttle or the slide would get slightly stuck and if I force the throttle to go back it would lower the idle. But this does not happens often, sometimes just in the middle of the ride.
But I definitely can't idle the bike for more than ~1m, it simply stops. I have cleaned the carb more than 10.000 times, changed needles and adjusted the float.
The float adjustment turned out really nice as I was able to lean the engine a little bit, spooge decreased. I don't think running a LeoVince instead of the FMF "spooge trap" (did you guys ever looked at its bowels ?) explains the enormous decrease of spooge itself .

Air screw makes no difference at all if I back it out 2 or 3 turns from full in and bike bogs off idle just like in this Slaven's video http://www.youtube.com/watch?v=zVzqqpgviyI. The air screw not having any effect tells me I should go to lower one but the bog of idle tells me the opposite. The spooge on the pipe when riding technical stuff (lower revs) tells me it's too rich...

At the moment I have:

42 pilot
NOZI #3
180 main
AS 1,5
Slide is 7
38 PWK ASII
Sea level
~15?C

It starts just fine with the choke but if I close it engine stops, I have to compensate with the throttle . When it warms up a bit manages to idle but after a while it shuts down.

I would not like to go with the head mod at this moment especially because it will make the engine to run a tad hotter . I do a lot of technical stuff and I don't want the engine to boyle.
Should I try the 45 pilot?

It sounds like you've answered your own question. If the bike bog when you bring the AS out then IMO the AS is having an affect. It may not be affecting your idle speed in a big way, but its definitely changing the air-fuel mixture. Try bumping up the idle speed a touch if you have to and see if it helps. Honestly depending on conditions my bike won't idle for minutes on end, especially if I've been riding single and loaded it up a bit. I don't expect it to either. The main thing is that it doesn't stall when I close the throttle/on downhills easily. Definitely try a 45 pilot and go for a ride and see how it feels. Also like Slavens says, make sure you do all this when the bike is at full temp and the engine has been cleared out/run hard.

The richness IMO is with the NOZ/N1E needle tapers too. They are too rich for my conditions in Australia off the bottom and always resulted in mucho spoogo and really poor fuel consumption. Its clear you have different fuels/fuel requirements though as my bike wouldn't really run at those settings. I'd exect to be 40 NOZI#2/1 172, so in saying that it also makes sense that you'd want to be a few sizes larger on the pilot and main. Give the bigger pilot a go and you'll soon determine if it was a step in the right direction.

My general advice on the pilot circuit is to set the slide height manually and visually to be a few mm open. Then pick your needle and cycle through pilots with the AS 1.5 turns out, until you find the one that works best. Then AS and idle speed to dial it in for idle and response.

 

[Vindicator]

The richness IMO is with the NOZ/N1E needle tapers too. They are too rich for my conditions in Australia off the bottom and always resulted in mucho spoogo and really poor fuel consumption. Its clear you have different fuels/fuel requirements though as my bike wouldn't really run at those settings. I'd exect to be 40 NOZI#2/1 172, so in saying that it also makes sense that you'd want to be a few sizes larger on the pilot and main. Give the bigger pilot a go and you'll soon determine if it was a step in the right direction.

Thanks for the input, I really appreciate. I also tried a N8RG and although I liked it in the pumpkin I don't in the GG. I lost the "tractor" feeling on low revs.
I use the 180 main because I'm a bit "paranoid" with dry cylinders . I want to make sure it does not starves when WOT but I admit I could go a little lower .
I will give it a try with the 45 and then report back, I jut wish it would be easier to take the carb out (only major hassle I found so far in this bike )

 

[Jakobi]

No need to remove the carb. With stock tank you can loosen the pipe clamps each side, rotate the carb towards you, remove the cap and slide, and then rotate the carb away and access the pilot and main via the drain plug. Sometimes its a tight fit with one of the overflow guides and the chain/front sprocket guard. Easily manipulated past.

These days I usually avoid changing pilots and mains unless if I have to or unless the carb is out for something else and just change needles by removing the tank and shrouds. 3 x bolts, then the 2 in the carb cap.

 

[Vindicator]

Thanks for the input, I really appreciate. I also tried a N8RG and although I liked it in the pumpkin I don't in the GG. I lost the "tractor" feeling on low revs.
I use the 180 main because I'm a bit "paranoid" with dry cylinders . I want to make sure it does not starves when WOT but I admit I could go a little lower .
I will give it a try with the 45 and then report back, I jut wish it would be easier to take the carb out (only major hassle I found so far in this bike )

I finally had the chance and changed the pilot to a 45. This was done late in the evening so the only adjustment done was moving the air screw to 1,5 turns out . Went riding the next morning and after the bike warm up I definitely noticed an improvement. The bogging almost cleared and the torque on low revs increased, the bike always kept on going even when I thought it would stall . The conditions of this ride were not ideal, it rained like cats and dogs with some hail in the mix but no cold !!! ~15?C . Spooge increased and it tends to load up when lugging around but I think the trail we did was the culprit (no more than 4th gear), in any case I prefer to have it tuned on the richer side .
I'll report back when having done a proper adjustment.