125/150/250/300 KTM/HUS/GG jetting thread

sandman768
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sandman768 3/27/2022 10:04am
3/27/2022 10:04am
gahooligan wrote:
I still cannot get my 2022 125xc to pull clean from closed throttle at lower-ish revs. Initial pull away is fine but a 1st or 2nd...
I still cannot get my 2022 125xc to pull clean from closed throttle at lower-ish revs. Initial pull away is fine but a 1st or 2nd gear crusing to a snap open throttle does not respond and clutch or throttle play is needed. I am running the notched JDR 5.0 slide with jetting and PV settings from the first page, and thinking it is just a bit lean in that situation only. I have played with pilot and air screw as well as needle and cannot find a setting that works. Maybe the bike is just geared too tall?? It sucks because it runs great otherwise. My sons 85sx rips in comparison with ZERO hesitation even with me on it (140lbs is t saying much lol). Anyone end up here and have any suggestions?
Was jet block gasket replaced? Needle clip position?
gahooligan
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gahooligan 3/27/2022 10:45am
3/27/2022 10:45am
Gasket replaced. Clip position 2. Tried 3 but got a rich burble instead. Tried that with a leaner pilot and same issue. Float height is set at parallel with carb deck. I just cant get rid of that bog or burble. I cant find the happy middle.
AJ565
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AJ565 3/27/2022 4:29pm
3/27/2022 4:29pm
gahooligan wrote:
Gasket replaced. Clip position 2. Tried 3 but got a rich burble instead. Tried that with a leaner pilot and same issue. Float height is set...
Gasket replaced. Clip position 2. Tried 3 but got a rich burble instead. Tried that with a leaner pilot and same issue. Float height is set at parallel with carb deck. I just cant get rid of that bog or burble. I cant find the happy middle.
Use the other needle. When I was testing there was a point where one needle was too rich at one clip and too lean on the next. The other needle is a half position different so it will bridge the gap between the clip position on the needle you have now. Also you’re running a spark arrester? That’s going to mess with things too.
gahooligan
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gahooligan 3/27/2022 5:27pm
3/27/2022 5:27pm
Went back to stock silencer to get the turbinecore out of the equation. I will try the other needle or use a shim and see what happens. This thing must be really picky, like a woman.
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bdavis354
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bdavis354 3/31/2022 11:01am
3/31/2022 11:01am
Been waiting for this little jet block gasket to get replaced. JD Kit inally came in mail and just finished putting the carb all back together with full overhaul and Aj’s slide/jetting spec for 250sx , can’t wait to check it out asap. Will post my results. mail
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Mattshredsgnar 3/31/2022 11:41pm
3/31/2022 11:41pm
so I have a 2019 KTM250sx and I bought a JD jetting kit which said to use blue needle with 430mj and 32.5pj which has made my bike run very lean.AS is at like 1.25 and even richening it more didn't help. I saw a post about my specific bike which said it ran good with 43-71 needle with 450main and 35 pilot. im hoping this helps. im also at 1100 ft. at the 3rd clip. and I changed the jet block gasket that goes bad. id rather not have to get a new slide to be honest im not crazy fast I just want it to get richened up in a good way so I don't blow up my bike. any help would be appreciated
Mattshredsgnar 4/1/2022 12:21am
4/1/2022 12:21am
also been thinking about switching to t4 or t2 since I currently use 91 pump mixed 50;1. if I need to get a different needle and main which needle as I've seen quite a few different ones in the thread.
bdavis354
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bdavis354 4/1/2022 8:59am
4/1/2022 8:59am
Mattshredsgnar wrote:
so I have a 2019 KTM250sx and I bought a JD jetting kit which said to use blue needle with 430mj and 32.5pj which has made...
so I have a 2019 KTM250sx and I bought a JD jetting kit which said to use blue needle with 430mj and 32.5pj which has made my bike run very lean.AS is at like 1.25 and even richening it more didn't help. I saw a post about my specific bike which said it ran good with 43-71 needle with 450main and 35 pilot. im hoping this helps. im also at 1100 ft. at the 3rd clip. and I changed the jet block gasket that goes bad. id rather not have to get a new slide to be honest im not crazy fast I just want it to get richened up in a good way so I don't blow up my bike. any help would be appreciated
I have 2018 and bought the Jd jet kit, also agree it was garbage. The JD Jet Block kit is diff. It solves the pilot circuit and air screw issues that plague the TMX carb. As for jetting see the opening page for details. But from what I’ve gathered in this forum the bulk of the jetting is solved with slide swap to a 5.0,5.5,5.75 depending on your riding style. In conjunction with a needle swap. All the info is in this forum if you look at first page for baseline and adjust main/air screw based on elevation or how deep in the throttle you drive. I’m at sea level in Nc and these are my new baseline specs I’m going to try this weekend.

MJ 490
PJ 32.5
AS 1.5 turns out
Needle jet S4
Needle 42-75 on the 2nd clip
Slide 5.5
JD Jet block gasket kit installed
Fuel mix 50:1 Motorex T2 w/pump gas 93 ethanol free

AJ565
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AJ565 4/1/2022 11:39am
4/1/2022 11:39am
Mattshredsgnar wrote:
so I have a 2019 KTM250sx and I bought a JD jetting kit which said to use blue needle with 430mj and 32.5pj which has made...
so I have a 2019 KTM250sx and I bought a JD jetting kit which said to use blue needle with 430mj and 32.5pj which has made my bike run very lean.AS is at like 1.25 and even richening it more didn't help. I saw a post about my specific bike which said it ran good with 43-71 needle with 450main and 35 pilot. im hoping this helps. im also at 1100 ft. at the 3rd clip. and I changed the jet block gasket that goes bad. id rather not have to get a new slide to be honest im not crazy fast I just want it to get richened up in a good way so I don't blow up my bike. any help would be appreciated
You can waste your time with that like many other have or you can get the slide and fix the problem. That’s the key to all of this. It’s a night and day difference over the JD kit.
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mxstate
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mxstate 4/1/2022 12:17pm
4/1/2022 12:17pm
Mattshredsgnar wrote:
so I have a 2019 KTM250sx and I bought a JD jetting kit which said to use blue needle with 430mj and 32.5pj which has made...
so I have a 2019 KTM250sx and I bought a JD jetting kit which said to use blue needle with 430mj and 32.5pj which has made my bike run very lean.AS is at like 1.25 and even richening it more didn't help. I saw a post about my specific bike which said it ran good with 43-71 needle with 450main and 35 pilot. im hoping this helps. im also at 1100 ft. at the 3rd clip. and I changed the jet block gasket that goes bad. id rather not have to get a new slide to be honest im not crazy fast I just want it to get richened up in a good way so I don't blow up my bike. any help would be appreciated
AJ565 wrote:
You can waste your time with that like many other have or you can get the slide and fix the problem. That’s the key to all...
You can waste your time with that like many other have or you can get the slide and fix the problem. That’s the key to all of this. It’s a night and day difference over the JD kit.
Listen to AJ...
For a short time I just had the slide as I was waiting for the other parts but that alone was a main game changer.
The jets/needle/needle jet were what made this whole setup a complete and reliable package.
I'm not crazy fast either but I could feel the difference and most important it cured the inconsistency as temp/humidity would change.
queen of spodes 4/3/2022 1:12pm
4/3/2022 1:12pm
queen of spodes wrote:
As suspected: [img]https://p.vitalmx.com/photos/forums/2021/12/08/521823/s1200_jetblockfailure.jpg[/img] Got the new JD jet block gasket installed, loc-tite on the two screws upon reassembly. This should clear up the blubbery idle. Maybe...
As suspected:



Got the new JD jet block gasket installed, loc-tite on the two screws upon reassembly. This should clear up the blubbery idle. Maybe it'll help with the weird flat spot off idle through when the powerband hits hard too, but - I'm prepared to do some PV tuning at the track.
Welp, I bought a house and hadn't ridden the bike for six+ months until yesterday.

Rode at the local MX track with the new JD Jetting block jet kit installed. Much, MUCH better. Bike pulls clean and smooth off idle into the mid-range hit. Minimal amount of smoke (some just not belching like before).

There is still a hint of blubber (pang pang-pang-pang) when chopping the throttle, but it runs so clean everywhere else I'm not super worried about it. Using Amsoil Interceptor at 50:1 with same jetting as Option A in first post of this thread.
gahooligan
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gahooligan 4/3/2022 2:58pm
4/3/2022 2:58pm
Aj , i tried the richer needle and the 125xc runs great everywhere except right off the bottom. I just cant get it to pull clean it either bogs or burbbles. I cant find an in between. I have tried pilots, AS adjustments, needles, etc. Cant get rid of it. Do you think its possible the 5.0 is just too much for the 125 and I need a slide cut to 4.5 or 4.75?
AJ565
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AJ565 4/3/2022 4:18pm
4/3/2022 4:18pm
gahooligan wrote:
Aj , i tried the richer needle and the 125xc runs great everywhere except right off the bottom. I just cant get it to pull clean...
Aj , i tried the richer needle and the 125xc runs great everywhere except right off the bottom. I just cant get it to pull clean it either bogs or burbbles. I cant find an in between. I have tried pilots, AS adjustments, needles, etc. Cant get rid of it. Do you think its possible the 5.0 is just too much for the 125 and I need a slide cut to 4.5 or 4.75?
That would make it richer and the problem worse. Did you notch the slide at all?
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gahooligan 4/3/2022 5:24pm
4/3/2022 5:24pm
Yes. I notched the slide. It its from a slow roll. When revving on the stand, i can get a clean pull by richening the pilot. (32.5 at 1.1/4 turn on the AS) but the bike still acts like it has a lean bog from a rolling "whack it open" event. If i richen the AS i get a rich burble, no in-between. Yesterday we rode down a dirt road between trails. To wheelie I had to clutch it up. Should i not be able to whack it open, pull clean and wheelie? I realize these seem like "childish tests" but its the best way to describe the issue. At full tilt riding woods it rips, with slight spooge even, but it just will not pull clean off the bottom with a whack open throttle. It acts like a four stroke that is missing the accelerator pump squirt. I dont get it... maybe I am just asking too much.
FGR01
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FGR01 4/3/2022 5:50pm
4/3/2022 5:50pm Edited Date/Time 4/3/2022 5:52pm
gahooligan wrote:
Yes. I notched the slide. It its from a slow roll. When revving on the stand, i can get a clean pull by richening the pilot...
Yes. I notched the slide. It its from a slow roll. When revving on the stand, i can get a clean pull by richening the pilot. (32.5 at 1.1/4 turn on the AS) but the bike still acts like it has a lean bog from a rolling "whack it open" event. If i richen the AS i get a rich burble, no in-between. Yesterday we rode down a dirt road between trails. To wheelie I had to clutch it up. Should i not be able to whack it open, pull clean and wheelie? I realize these seem like "childish tests" but its the best way to describe the issue. At full tilt riding woods it rips, with slight spooge even, but it just will not pull clean off the bottom with a whack open throttle. It acts like a four stroke that is missing the accelerator pump squirt. I dont get it... maybe I am just asking too much.
Some thoughts...

#5 slide is definitely not too lean for a 125. Mine, and others, are barking with it. Mine is on a TC125 doing full moto so I'd expect an overly lean slide to hurt me worse than you.

Float height - Maybe you've got this too low/lean. How are you measuring? Tilted at an angle where it just touches the plunger or totally upside down?

Slide notch - I am running no notch and a 35 or 37.5 pilot depending on temps. Is anyone successfully running a notch on a 125? I can't recall.

What fuel, oil, and ratio are you running?

Needle diameter - in addition to the pilot and air screw, perhaps you ight do well to start playing with needle diameter. This setting overlaps/interacts with the pilot.

Filter - is your filter perhaps overly dry and allowing too much air?

gahooligan
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gahooligan 4/3/2022 6:26pm
4/3/2022 6:26pm
Good thoughts FGR01

Maybe I need to go revisit the pilot. You are richer than me and it is in the 60s-70s °f here. Does yours still idle?
AJ suggested the notch for wood riders which is why i notched the #5.
Float was set parrell to carb body at tilt with float just touching the seated needle, not completely upside down depressing the pin. If you shut the fuel off on the stand you can hear/feel it go lean pretty quickly. It was low originally and I adjusted. Do you think I am now too high?
I have ran castor 927 and motorex(current) 2t both at 40:1 with the same results on my 125 and the sons 85sx. His bike is spot on now with jetting and freaking rips bottom to top with zero hesitation and almost zero spooge in the woods. Trying to get mine there.
Bike is new, Filter oil "feels" good and filter is still clean as we have not had dusty conditions yet. I could try re-oiling.

Thanks for the input. I look forward to dialing this last bit in.
bdavis354
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bdavis354 4/3/2022 6:41pm
4/3/2022 6:41pm
gahooligan wrote:
Aj , i tried the richer needle and the 125xc runs great everywhere except right off the bottom. I just cant get it to pull clean...
Aj , i tried the richer needle and the 125xc runs great everywhere except right off the bottom. I just cant get it to pull clean it either bogs or burbbles. I cant find an in between. I have tried pilots, AS adjustments, needles, etc. Cant get rid of it. Do you think its possible the 5.0 is just too much for the 125 and I need a slide cut to 4.5 or 4.75?
Are your reeds good condition???
FGR01
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FGR01 4/3/2022 6:44pm
4/3/2022 6:44pm
gahooligan wrote:
Good thoughts FGR01 Maybe I need to go revisit the pilot. You are richer than me and it is in the 60s-70s °f here. Does yours...
Good thoughts FGR01

Maybe I need to go revisit the pilot. You are richer than me and it is in the 60s-70s °f here. Does yours still idle?
AJ suggested the notch for wood riders which is why i notched the #5.
Float was set parrell to carb body at tilt with float just touching the seated needle, not completely upside down depressing the pin. If you shut the fuel off on the stand you can hear/feel it go lean pretty quickly. It was low originally and I adjusted. Do you think I am now too high?
I have ran castor 927 and motorex(current) 2t both at 40:1 with the same results on my 125 and the sons 85sx. His bike is spot on now with jetting and freaking rips bottom to top with zero hesitation and almost zero spooge in the woods. Trying to get mine there.
Bike is new, Filter oil "feels" good and filter is still clean as we have not had dusty conditions yet. I could try re-oiling.

Thanks for the input. I look forward to dialing this last bit in.
Digger has said many times the notch makes the pilot circuit more "efficient". It puts more draw on the pilot so you have to run smaller pilots with the notch. I set mine up without the notch first just to try it and it ran so good I never bothered putting a notch in it. I run the 37.5 from about 40-85 degrees and the 35 pilot from 80-110 degrees. My bike will idle nicely but I have it set that it stalls in about 2-3 seconds. Again, my no-notch pilot specs won't directly work for you.

I'd be double checking the float. If I turn my petcock off it won't start going lean that quickly. I'd also check the reeds while you have the carb off just to make sure nothing weird is going on in there.

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gahooligan
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gahooligan 4/3/2022 7:04pm
4/3/2022 7:04pm
Just installed a vforce 4 block to eliminate factory reeds. Lol. Not like i needed it. Factory stuff looked pretty damg good with no gaps. Maybe i will raise the float a bit and play with richening the pilot, not worrying if it will idle for extended periods 😄 Currently it will idle indefinitely at a moderate idle (higher than most mx for sure probably but not absurd. I stop often in the woods and wait for my son) I seriously appreciate all the advice from eveyone!!
digger
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digger 4/3/2022 7:21pm
4/3/2022 7:21pm
gahooligan wrote:
Aj , i tried the richer needle and the 125xc runs great everywhere except right off the bottom. I just cant get it to pull clean...
Aj , i tried the richer needle and the 125xc runs great everywhere except right off the bottom. I just cant get it to pull clean it either bogs or burbbles. I cant find an in between. I have tried pilots, AS adjustments, needles, etc. Cant get rid of it. Do you think its possible the 5.0 is just too much for the 125 and I need a slide cut to 4.5 or 4.75?
I see that you're trying to jet a 22' KTM/Husky model 125. I spent 2 days working on 2 different bikes trying to get them to jet cleanly, or to atleast get them to a point that I thought was acceptable, I never achieved that. I also had 19' and 20'(125's) bikes there as well, and they would do exactly as I would expect them to do jetting wise. But those 22's, I was never able to get that bog that you are describing out of them, and I tried everything. I had my hands on everything in those carbs and nothing I changed made much of a difference. It was super frustrating. I even had him try a 38mm Keihin PWK at one point with a jetting setup that was super rich and It still bogged off the bottom. There is something wrong with those bikes that's not right. I'm not sure if it's a power valve or an ignition/electrical issue, but something isn't right. The one thing we did take away from it though, is that the red power valve spring from the 250/300's makes the bike much more responsive off the bottom.
gahooligan
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gahooligan 4/3/2022 7:41pm
4/3/2022 7:41pm
Digger, good to know I am not crazy!! I will source a red spring and make it the best I can. Thanks for the input, that is imprtant and valuable info before i waste a bunch of time.
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Hammer 663s 4/4/2022 3:17am
4/4/2022 3:17am
Could this be related in any way to the reported crank issues the 22 Austrian 125s are having? I’ve read here that there’s a new crank supplier, some cranks were pressed too tight, KTM is providing a new CDI to limit revs to protect motor, owners have reported multiple low-hour failures. Could a bad crank cause an unaddressable “bog”?
gahooligan
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gahooligan 4/4/2022 3:41am
4/4/2022 3:41am
Hammer663s
Have a link to thst post?
Sounds like a BS answer to the issue. Especially considering the price for a 125 and early failures of the engine.
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FGR01 4/4/2022 6:53am
4/4/2022 6:53am
I believe in that thread about the bad cranks there is one person who says they once had a bike with a crank pressed to tight and it exhibited symptoms like we see here - a "bog" (likely crank slow to spool up with resistance) but then blubbery if you tried to richen to tune it out.

Gahooligan, seems you need to check if the recall applies to your bike. I know if it was me, even if they did the "recall" (Swap ECU), I'd pull the cylinder so I could spin the crank, see if it is tight, and measure the thrust washer side play. Luckily pulling the jug is super easy on these bikes.
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gahooligan 4/4/2022 8:50am
4/4/2022 8:50am
I started reading that thred and digger is in there with the comments. I m going to be super pissed if i have to do a bottom end on a brand new bike.
stimacr
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stimacr 4/4/2022 4:44pm
4/4/2022 4:44pm
Just curious for those who did the Jarvis mod. I was thinking about giving it a go. What are yall thoughts on just filing the slide, drilling the holes on the nut and the plastic piece? I wont have the S4 tube or the 42-75 needle.

Current bike is a 2022 GasGas MC250. I ride 5k to 7500. Not on track mostly just on Desert whoop trails, sand washes, turn tracks and some dune like riding. Southern Colorado/Northern New Mexico

Looking for so lower end power/throttle response, running yellow PV spring still but have tried all 3, like the yellow at close to stock turns. Trimmed the back of my airbox cover as well (hand hold)

Current jetting is from the manual and have terrible MPG. Doing my first Webe race in 2 weekends. Last ride ended with some spooge. I will be swapping a turbine core 2.1 for the race (need spark arrestor)

IJ-32.5
NDL-42-71
POS- 3
MJ- 430

Thanks

Ryan
AJ565
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AJ565 4/4/2022 5:14pm
4/4/2022 5:14pm
stimacr wrote:
Just curious for those who did the Jarvis mod. I was thinking about giving it a go. What are yall thoughts on just filing the slide...
Just curious for those who did the Jarvis mod. I was thinking about giving it a go. What are yall thoughts on just filing the slide, drilling the holes on the nut and the plastic piece? I wont have the S4 tube or the 42-75 needle.

Current bike is a 2022 GasGas MC250. I ride 5k to 7500. Not on track mostly just on Desert whoop trails, sand washes, turn tracks and some dune like riding. Southern Colorado/Northern New Mexico

Looking for so lower end power/throttle response, running yellow PV spring still but have tried all 3, like the yellow at close to stock turns. Trimmed the back of my airbox cover as well (hand hold)

Current jetting is from the manual and have terrible MPG. Doing my first Webe race in 2 weekends. Last ride ended with some spooge. I will be swapping a turbine core 2.1 for the race (need spark arrestor)

IJ-32.5
NDL-42-71
POS- 3
MJ- 430

Thanks

Ryan
You’re wasting your time. Drilling holes in the bottom of the float bowl does nothing, same with the plastic. You can read through the whole thread where others try to bandage the problem and then end up swapping to what’s laid out in the specs. on the first page to get their bikes right.
stimacr
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stimacr 4/5/2022 9:21am
4/5/2022 9:21am
stimacr wrote:
Just curious for those who did the Jarvis mod. I was thinking about giving it a go. What are yall thoughts on just filing the slide...
Just curious for those who did the Jarvis mod. I was thinking about giving it a go. What are yall thoughts on just filing the slide, drilling the holes on the nut and the plastic piece? I wont have the S4 tube or the 42-75 needle.

Current bike is a 2022 GasGas MC250. I ride 5k to 7500. Not on track mostly just on Desert whoop trails, sand washes, turn tracks and some dune like riding. Southern Colorado/Northern New Mexico

Looking for so lower end power/throttle response, running yellow PV spring still but have tried all 3, like the yellow at close to stock turns. Trimmed the back of my airbox cover as well (hand hold)

Current jetting is from the manual and have terrible MPG. Doing my first Webe race in 2 weekends. Last ride ended with some spooge. I will be swapping a turbine core 2.1 for the race (need spark arrestor)

IJ-32.5
NDL-42-71
POS- 3
MJ- 430

Thanks

Ryan
AJ565 wrote:
You’re wasting your time. Drilling holes in the bottom of the float bowl does nothing, same with the plastic. You can read through the whole thread...
You’re wasting your time. Drilling holes in the bottom of the float bowl does nothing, same with the plastic. You can read through the whole thread where others try to bandage the problem and then end up swapping to what’s laid out in the specs. on the first page to get their bikes right.
So I read the first post and just have a couple of questions. I use pump gas and 60:1 ratio, I wouldn't hate to increase my oil ratio just for some more lubrication.

Bike Spec- 2022 Gasgas MC250, Airbox trimmed and turbine core 2.1 5k-7500' elevation

What elevation are your spec for?

Sounds like minimum I should do the following:

5.5 Slide
S4 tube
42-75 or a 43-75 Which is better for elevation?

Any other suggestions?
Mattshredsgnar 4/5/2022 12:13pm
4/5/2022 12:13pm
Mattshredsgnar wrote:
so I have a 2019 KTM250sx and I bought a JD jetting kit which said to use blue needle with 430mj and 32.5pj which has made...
so I have a 2019 KTM250sx and I bought a JD jetting kit which said to use blue needle with 430mj and 32.5pj which has made my bike run very lean.AS is at like 1.25 and even richening it more didn't help. I saw a post about my specific bike which said it ran good with 43-71 needle with 450main and 35 pilot. im hoping this helps. im also at 1100 ft. at the 3rd clip. and I changed the jet block gasket that goes bad. id rather not have to get a new slide to be honest im not crazy fast I just want it to get richened up in a good way so I don't blow up my bike. any help would be appreciated
AJ565 wrote:
You can waste your time with that like many other have or you can get the slide and fix the problem. That’s the key to all...
You can waste your time with that like many other have or you can get the slide and fix the problem. That’s the key to all of this. It’s a night and day difference over the JD kit.
So if I were to mod my 4.0 slide I read that you just cut the big arch down 1mm for 5.0? And the little tiny notch are we supposed to make that a rounded arch too? how deep and how wide?

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