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55431934000 JET NEEDLE ''6GAY69-74''
I get the different taper and that its a 6-series and 2.74 diameter, but 69-74??? Whats the purpose of this odd thing? Must be a VERY rich needle?
I know I used to run the 17-62 needle from an rm125 in my 17 and it ran really good
But how does it compare to 6BFY43-75 or any other of the 6BFY series? Sorry if this has been discussed time and time again, but the mikuni taper degrees and sec/mins is confusing. Especially so when you dont know where to place it in terms lean or rich from what you already know (6BFY needle chart).
Edit: The 6BFY series is B: 0º 30, F:
1º 30' and Y: 6º 15.
The 6GAY69-74 is G: 1º 45', A: 0º 15' and Y: 6º 15.
I read a bit about tapers and it seems like the G is steeper and A is not as steep as the B. Would this equal a leaner first part and equal last part? The 69 still confuses poor me tho.
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Edit: it is strange that they list it on the fiche for the carb and not in the manual for the bike. Stuff like that makes me crazy curious.
I recieved the 6GAY69-74 needle yesterday and put the needle in on 2nd clip just because I am curious. It actually ran pretty good. Rich from 1/2 to 3/4. AS at 1 1/4, 32,5 pilot, 520 main and 5,75’ slide. The spec needs refinement, but it could work.
For some reason I think this needle is odd, but still it actually worked pretty good. This may sound idiotic, but it reminds me a bit of the NECJ needle on the Keihin carburated bikes as in the stock needle series had less taper on the first parts of those needles. The NECJ was thicker and more of the (seemingly) same taper on the entire needle.
Digger or AJ, could you shed some light on this? My experience on needles and tapers isn’t as good as yours and I think (and hope) you guys would have some answers.
I know this is a great resource for tuning the Mikuni, does anyone have the hot ticket for the Keihin?
Thanks!
My bike had the powevalve screwed in a couple turns and it was either all on or all off. I turned the powevalve all the way out and it helped a lot.
I have the sputter around 1/8th throttle, always have, and I am trying to eliminate it.
Suzuki P/N - 13383-36FR0
I use that needle as well, guys on KTM talk talk about it, works great for mx
I have already written some messages here but I wanted to share with you my experience in jetting on Husky TC 125 2021.
I live in Italy and I use this bike to race in enduro (national championships at a good level) and in enduro it often happens to use the bike in "walking" mode (ie high gears and low gas ...) and when you are here the bike turns out to be excessively rich with bad power delivery.
I have really tried them all (setting, needle, slide and so on ...)
I tried the setting recommended by AJ or DIGGER, but probably with the quality of fuel we have in Europe, with that setting the bike was ever too lean.
I tried various settings with the JD KIT, the bike worked more or less well but at high revs the bike leaned a lot.
In the end I found a setting where the bike works quite well :
max 500
min 45
R8 needle jet
slide 4
needle 6 DEY 15-74 at the third notch - this is the needle that the 2011 Husqvarna CR 125 ( those made in Italy) fitted as stock
With this setting, the power delivery no longer gets "dirty" as before and the bike runs well.
I am happy to have shared my experience with you.
I’ve tried the settings from the first page.
Think I’ve got a lean bog just before 1/2 throttle, so I’m going to experiment with needle clips and other needles. I did the cut in the #5 slide aswell. I’m new to with jetting 2 strokes, it runs awesome from from idle to wot except the bog, which I think is a lean bog might be the other way around also.
I’m at sea level and and it’s around 32F here at the moment.
Pit Row
I went ahead and modified my slide to a 5.5, notched the front, and installed all new jets as listed on the first page for my 2019 KTM250SX. Fired up the second kick and was nice and crisp, idled good, and had no hesitation when letting idle for a minute and quickly opening throttle. The jet block gasket was deformed as most and replaced that as well. Only took a quick run up the street since the blacktop was wet from raining, but all seemed good going thru the gears, can't wait to hit the track soon if the weather ever clears up around here. May have to mess with the pilot jet at some point (smaller) I think? When turning in the air screw, it didn't almost die when closed. However, It was 50deg and raining when testing yesterday, so it may be ok when it gets above 70, but open to suggestions? For reference I used the 490MJ, 32.5PJ, S4, and 42-75 needle at 52:1 on gas. Thx
I do have a bog in midd throttle before it gets going again if I crack the throttle wide open. It's fine if i roll the throttle on. would like to get rid of that bog though, my jetting skills are limited. I have replaced the jet block gasket with the JD one.
Running the following at the moment.
This is at 80 to 100 meters above sea level. (260/330 feet)
0C to 5C or 32F to 40f
MJ 540
PJ 37.5
Needle Jet S4
AS 1.5
slide 5.0 with notch.
Needle 42-74 on the 2nd clip
Needle jet S4
PV at stock setting, whatever that is.
Fuel mix 40:1 with 98 octane pump gas.
What should I try next to get rid of that bog?
I've tried to lower the needle to 3th and 4th clip position and 35 PJ and it ran way to rich on the 1/8 to 1/4 throttle. Should I go lower on the PJ and try 3 clip again?
Or go second clip with the 43-74 needle instead, thinks it's a half stop richer that the stock one?
Perhaps go down to a 32.5 PJ as i have #5 slide and notched it and go to 3rd or 4th clip position on the stock needle?
Bike runs overall good with the needle on the second clip position before and when it get passed that midd throttle bog it hauls ass to say the least.
Killed the bike when the bog occurred and the spark plug is whiteish.
All suggestions is more than welcome
Have a great day you guys
I would try 500mj / 35 pj and see how that goes. You could try the first clip position too. The other question is are you having a lean bog or is the engine loading up? If you are seeing a big cloud of smoke then it clears out you are too rich. If no smoke you might be too lean in the mid range and need to try a 42-73 or 72 needle. Plug being white (I assume dry?) makes me suspect you are lean.
Also at those temps make sure you have at least the partial radiator cover on the left rad.
If I move the needle to the first clip wouldn't that make it leaner in the mid range?
when I moved the clip to 3rd and 4th clip if I remeber correctly it made the mid range richer and sorted the bog (not sure about this, can't remeber). But made the 1/8 - 1/4 to rich.
Perhaps if I go down to a 32.5 PJ and the clip to 3rd could sort it out? Read somewhere that if you run the #5 slide with the notch it would make the PJ curcuit more efficient so you could run smaller pilots.
Feels like i'm lean in the mid throttle and the spark plug looks white to me. It takes a second or two before a surge of power comes on after the bog
So maybe
Main jet: 490 or 500
Pilot jet: 35 (Or the 32.5 pilot as I've notched the #5 slide to make it more efficient)
Needle: 6BFY42-74 3rd clip (standard needle)
Or
Main jet: 490 or 500
Pilot jet: 35 (Or the 32.5 pilot as I've notched the #5 slide to make it more efficient)
Needle: 6BFY43-74 2nd clip (Would make it a half clip richer?)
Or maybe it need the 35 PJ now in this cold weather and I assume the PJ curcuit has some effect at mid throttle aswell.
Only have those 2 needles at the moment
6BFY42-74 (standard needle)
6BFY43-74 which I think is half clip richer
Should I buy something else?
I have the full radiator cover on the left rad.
Was thinking that I had to put the needle clip on the third clip and than drop the pilot jet to a 32.5? More fuel to 1/2 throttle and less in the pilot circuit to compensate for the richer needle position which also effects the pilot curcuit somewhat?
And again I’m new to this jetting so i'm just speculating at this point and really appreciate all of you insight and advice.
Best regards
Will report back after my ride this weekend.
Thanks to both Aj and wrc77
Ended up with
Main jet: 520
Pilot jet: 32.5
The 43-74 needle at the third clip.
As 1.5
Float height set at 8.3mm
Runs crisp and clean with no hesitations or bog at sea level and around 28-32F in temperature.
Was running the 42-74 needle (standard needle) at 3rd clip and it was better but still bogged when quickly going wot.
So tries 4th clip and it was running rich and remembered that the 43-74 needle was half a clip richer so tried that at 3rd. I’m very pleased and happy with my bike now.
Got a question regarding the power valve, mine was stuck and wasn’t able to turn it at all. So took it apart at it was cross threaded. Must have been from the factory.
Anyways that’s all sorted now and read that some people like it 1.5 to 1.75 turns in. Is that from all the way counter clockwise to the “hard stop” or is it from flush with the case? I did not check where is was before I took it apart. So I don’t know the “standard” setting.
Hard stop or flush with the case?
Best regards
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