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Location
Merced, CA
US
Hey guys I have my sons 125 and I was wondering what a lot of you guys have had success with as far as carb switch or jetting? I just ordered a red spring for it and want to set that and do a top end soon. We do mostly just moto. What do you guys recommend?
Call Lynks racing. They had mine screaming with Keihin carb
PWK + STIC metering block. You can not beat that combination. Ask Steinke about that. When I did my Husky 125 with the PWK and Stic modded carb , that alone felt like I had sent the motor off to Tom Morgan. It was night and day , way stronger from bottom and gained a LOT of over-rev.
I opened the airbox , milled the head , cleaned the ports , put a great exhaust on there and she felt really good compared to stock. I tried the PWK + Stic....and that alone was the most incredible boost of power I ever did to that bike. I talked to a few guys with it , and they swore by it. After talking to Steinke , I had to try it. One of the best pieces of advice a fast guy has ever given me. I have ridden a modded 150SX / smart carb or electron carbed bike and it didn't pull anything like my bike in the mid range , and definitely not on the top.
Our bikes are running extremely well since my son downloaded an app called "JettingKTM" in the app store. We just run the stock carb with zero modifications. I used to like Lectrons because we never could get the jetting dialed in. But now much happier with stock carb and the jetting. The app uses temperature, humidity, etc from your phone's location to give you very good numbers. It's a one time purchase of around $5. I have not afflication with them, just a happy customer.
That's a pretty cool app
The Shop
https://www.vitalmx.com/forums/Tech-Help-Race-Shop,42/KTM-HUS-125-150-2…
Hey bud thank you for the info. Who sells that carb and stic mod? That would be cool
That's pretty cool, never heard of it before.
Hopefully ktm have better stock settings since it came on the bikes in 2017.
There is a great jetting thread on here that works really good. The mikuni runs crisp and clean, it's a great carb once setup.
We run the pwk Stic setup, I was an early adopter and ran into the silly setting issues with my own carb. The new ones they send out, the bike makes mega acceleration, can be abrupt... really good on our husky 125 and ktm150
So where did u guys get the pwk with stic metering block?
From George Boswell himself. I'll see if i can find the link. I think jd jetting sells them also,setup ready to go
Website out of date, I'd call...
http://www.sticsupertorque.com/
https://www.vitalmx.com/forums/Tech-Help-Race-Shop,42/KTM-HUS-125-150-2…
You're welcome. For my 125 I went with a 36mm pwk from JD jetting. With the Stic , I got mine through Derek at HP performance here https://www.hpracedevelopment.com/stic-metering-block.html#/
If you go that route , make sure you get the correct carb / Stic combo. I believe our carbs on the Austrian bikes are short bodies.
Side note , I think it was the best mod I've ever done to my TC 125 , or probably any bike ever. BUT I did not care for it in my TC 250. It has a pinging / knocking sound I couldn't get rid of , but the main reason was it made my 250 violently fast. Like unrideable fast. The mid range and top end pulled a lot harder than what I wanted. I took it out after a couple rides and sold it here. I did keep the PWK on the 250 though. 38mm on the 250 and 36mm in the 125.
I did all the recommended modifications to the Mikuni carb (check the seal, vastly different jetting, float height, recutting the slide….) and could get it to run well, but it was still sensitive to temperature and altitude changes. Found a Keihin 36 online and am much happier with that. Response is better and it’s less finicky to setup.
Don‘t waste time on the Mikuni if you’re not really good at jetting.
This engine was designed with/for the Keihin carb.
edited: typo
I found that to be exactly what I went through. The Mikuni made good power when jetted right , but it seemed like a slight 15 - 20 degree temp change , I'd have to rejet. The PWK even stock was way more forgiving. Plus, the Stic was only made for the PWK.....and that alone is such a big difference, that you need to experience it , to believe it.
I have the exact opposite experience. We've been running AJs jetting on our 2020 125SX since day 1. I only reject to a bigger pilot & main when it's gonna be below 30f at the track. Otherwise, 35-95f I don't touch it. 40:1 VP110 cut with 92 pump for about 103 octane. We don't change altitude much here so can't speak to that. Lots of people say Keihen or STIC or Lectron but ours is fast on the Mikuni. Last weekend the only guy regularly beating my boy to the holeshot was an AMA pro license holder on a 450 (mixed classes due to low turnout). Now, my kid is 115 soaking wet and the motor is by Haeseker Racing but still.....power is NOT an issue.
I guess if you can ride a 125 WFO all the time you might feel a difference, but that's less than .05% of the people here.
I agree if you can just pin it all the time. I heard that the Mikuni can make the most power and a lot of teams run it in EMX.
However, I ride mostly hardpack tracks and need some control. For that I like the Keihin much better.
I tend to use rear sprocket size and power valve settings to control power delivery. Right now we are riding sand (winter track) but will go to clay (wet to tacky) soon, then hardpack in the summer. Same carb all the time and there's no real big hit anywhere when the PV is set properly for it's engagement. Spring color and turns make a big difference. We have 48-51T rears we change depending on track length and speeds too.
IMHO race 125s are not set and forget machines. They require tuning for specific conditions. And lots of top ends! I barely even change map settings on my 350. Tire pressure and ride it.
I just downloaded it. Very cool app. Having a 50sx and 250sx I will definitely be double checking my settings during the riding season. Thanks.
Pit Row
I've ridden lectron, mikuni and stic on my 150.
Lectron was very bland, mikuni runs great... clean and crisp.
Stic makes very good power, dyno proven... especially at partial throttle. Stic does make the 150 a bit wild and abrupt, it definitely gets you out of a corner. Not sure I'd want a stic on 250 mx smoker
What version of the STIC are you running now Bruce372? I have an original version on a 2019 KTM 150sx that seems to work pretty well for moto.
They make a stic for the mikuni also? My sons have a 21 and 22 ktm 125sx and do only moto
The 22 seems to be different than the 21. Lots of people in the jetting thread are struggling to get it working right. Not sure anyone has found a reason yet. 22s also reporting higher crank failure rates due to a sourcing change. I'm sticking with our 20 and rebuilding it since Haeseker said it's one of the more reliable platforms he works on. And he does a LOT of KTM 2 stroke work.
114a with the jd stic red needle. 205 and 55 I think
Jeffro
what did you run for jetting on the 250 w the keihin?
thx!
Thanks bud i jist installed a red spring in their bike at stock set turns in. We will see this weekend if it works different. The carb for sure i want to do because like u said the 125 is picky so i want to be a little ahead of it at least
Hey bud there is 2 apps jetting ktm max performance 2.99 and the other is jetting ktm for mx enduro 5.99
I found the G2 #400 mud cam returns the throttle control and range back to stock. I've got the even more potent STIC Super X2 carb on my 200SX now and I made sure I ordered the G2 and installed them at the same time. My 115 tube tune was too abrupt for jumps right out of turns, sketchy 'point and shoot'.
FYI, there is a new STIC Super X2 cast carb now available. It's a very clean cast body made in the US! It has better tune-ability and includes the 2nd half of the complete design. Once RPM's leave the idle circuit range, the pilot circuit reverses flow and feeds air/fuel vapor to just above the main jet. The STIC likes to feed on more vapor, where as std carbs become over rich.
I installed it and the thing ran great 'as delivered'. I later installed an 80 pilot jet! with a larger air correction jet. Idle remained the same, as did the air screw and main jet. Keep in mind, the PWK on my 200SX uses a 45 pilot.
Post some pictures please
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