yet another no idle thread.

[mrkartoom]

Originally Posted by stainlesscycle

i have a scrap bst (bad valve body gasket - not available...) in pieces. if you want it i'll send it to you..maybe you can make use of the parts... let me know.

Thanks a lot for the offer, but I sold that LC4 a couple years ago to get my Husky. I only referenced it because it was so notorious to get set up good. This is bringing back memories of the 200 or so hours I spent jetting and modding that thing!

[GMP]

Stainless,

In addition to the slide, I would not rule out Jeff's comment on the worn carb nozzle. You did swap carbs, but they were both old, correct?

Try the needles and report back, its useful data for everyone.

[Jakobi]

Just went through all this myself. From an N1EF to N3EG to N3CH and finally N3EJ.

Each change the idle improved from initially not idling when warm to now idling really well. Also with each step leaner in needle diameter I had to step up one size in pilot to stop the idle hanging after a blip of the throttle.

If the needle is too fat and the pilot too lean, the air screw and idle screw will have very little effect until your wound in enough to pull over, at which point the idle is erratic depending on if the bike is cold or warm.

[stainlesscycle]

Originally Posted by GMP

Stainless,

In addition to the slide, I would not rule out Jeff's comment on the worn carb nozzle. You did swap carbs, but they were both old, correct?

Try the needles and report back, its useful data for everyone.

will definitely report back everything i find. i know once it's right it will be pretty obvious.

the motor i'm putting these on is fresh, has great compression and nice squish (1.2mm) - so i've pretty much ruled out motor issues. i've also switched new plug wire/end in.. reeds are carbon fiber, look good, but i'm putting new ones in anyways, so i know where they're at.

both carbs were old, but both carbs had idled in the recent past, and were put away when i switched to 36mm pwk.

i have no real way to measure if both nozzles are worn...i basically will try all needles in both carbs and see what works. i tried identical setups on both carb bodies, and the did act slightly different - one was always slightly richer on the bottom - i swapped choke valves and lowered the floats temporarily to 18mm to be sure it wasn't float or choke issues. so it is possible the richer one has an ovalled carb nozzle, or worn a/s seat, or something letting more fuel in......

[stainlesscycle]

swapped to brand new reeds, - went with non carbon fiber to see if that made a difference. no difference.

went to 38 pilot, no difference. will not idle no matter where i set airscrew or idle adjust. well - maybe it idles for half a second... riding around, i can just barely lean on the throttle and it'll not shut off. can't really set air screw since i can't really get it to idle on the pilot circuit...

choke appears to have no effect... i've switched 3 different choke bodies in and they all do the same thing...it never gets super rich/stutter from choke open .

plug coloration is not bad. it's only coloring intake side of plug though...

went back to 42 pilot - it has a slight stutter at 1/8 throttle so 40/38 is probably closer with ddk needle... i guess i wait for needles to try them out. if no effect, i'm assuming it's slide cutting time. don't know where else to go...

the worst part is it runs better than it ever has. easy to start, power everywhere. no lean bogs, will roll around at 1/8 throttle in 3rd gear and has no issues. will pull hard from idle to wot up a hill in 3rd (and i'll be on one wheel after 15 ft or so....) ..so it's jetted pretty close. when i shut throttle it drops right to where it should idle, then dies. super responsive, just no idle...

[Jakobi]

Originally Posted by stainlesscycle

swapped to brand new reeds, - went with non carbon fiber to see if that made a difference. no difference.

went to 38 pilot, no difference. will not idle no matter where i set airscrew or idle adjust. well - maybe it idles for half a second... riding around, i can just barely lean on the throttle and it'll not shut off. can't really set air screw since i can't really get it to idle on the pilot circuit...

choke appears to have no effect... i've switched 3 different choke bodies in and they all do the same thing...it never gets super rich/stutter from choke open .

plug coloration is not bad. it's only coloring intake side of plug though...

went back to 42 pilot - it has a slight stutter at 1/8 throttle so 40/38 is probably closer with ddk needle... i guess i wait for needles to try them out. if no effect, i'm assuming it's slide cutting time. don't know where else to go...

the worst part is it runs better than it ever has. easy to start, power everywhere. no lean bogs, will roll around at 1/8 throttle in 3rd gear and has no issues. will pull hard from idle to wot up a hill in 3rd (and i'll be on one wheel after 15 ft or so....) ..so it's jetted pretty close. when i shut throttle it drops right to where it should idle, then dies. super responsive, just no idle...

I had the same problem with the idle. The choke definately was working for me. I identified the idle problem to be to do with the straight diameter of the needle. I have been using the N3 range.

F too fat won't idle even with the idle screw right in.
G will idle with quite a bit of idle screw.
H will idle for days on end, even at full temp in gear.
W on order.
J idles well but when bumping up the idle screw results in a hanging idle that has to be brought down with the choke.

Have run them all with varying pilots. Feel that a 35 with the H diameter gives best off idle response. AS 1.5. Idles forever. Pulling the clutch at any time the revs fall back into said idle.

[stainlesscycle]

where are you at - elevation/temperature? it's approaching 95 degrees here.

[Jakobi]

Originally Posted by stainlesscycle

where are you at - elevation/temperature? it's approaching 95 degrees here.

Note my bike is a 2010 with PWK ASII 38mm so will be jetted leaner than the older models.

Australia ? Queensland ? Nth Cst & Tableland

Kuranda Weather
16.82?S 145.63?E 336m AMSL (1102.3622 feet)

Cairns Forecast
Today 27?C (80.6 degrees Fahrenheit)
Tonight 14?C

Now
23.8?C (74.84 degrees Fahrenheit)
Updated at 09:50 EST

Relative Humidity 49% -64%
Pressure 1016.2hPa

[Jakobi]

N3xx needle diameters
D=2.685mm
E=2.695mm
F=2.705mm
G= 2.715
H= 2.725
W=2.735
J= 2.745

Matching these against the Sudco charts my config would be the same diameter as an N.

Suggest you try a DDM or DDN. Should put you in the same clip with the same taper and just a leaner diameter to get your idle in spec.

[stainlesscycle]

yep - i'm at 2.695 diameter - definitely need a thicker needle..