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Only $10 for all 2026 SX, MX, and SMX series.
I am trying to get my 2022 125xc sorted. Riding woods in GA at about 600-800ft in the 60-70 air temp range.
I installed the jetting from the first page:
Replaced jet block gasket with JD jetting gasket
Set float height parallel to carb body using the side tilt method (should it be upside down)
JD Jetting 5.0 slide, notched as instructed
490 main
End up at 32.5 pilot
1 1/8 on AS
S4 nozzle
42-74 needle position 2
PV 1.75 in from full out
FMF turbine 2 to be legal
93 pump w 40:1 castor 927
(I got my sons 2019 ktm 85sx dialed and it doesnt spooge even with a turbine core 2 so I dont think its the castor 927 see spooge comments below)
This runs SO much better than stock!! I still have a slight unpredictable hesitation on the trails when whacking it to loft a mudhole or root. I tried going to 1.5 on AS and it made it worse. With a 30 pilot i had to run the AS at .5
I tried pos 3 on the needle and a 30 pilot thinking i was making up for a lean needle with the pilot and AS. It was worse. Went back to 32.5 pilot and it was worse. Both of these were now rich on the needle. Best i can get it is position 2 on the 42-74 and either the 30 pilot at .5 on the AS or 32.5 pilot at 1 1/8 on the AS.
Also thinking the 490 Main may be too much as I get spooge out of the turbine core (less than before) and it "speckles" the rear fender just reving on the stand (have read this may be the Turbine core itself).
Should i leave it and try the stock silencer, or do you guys have any advice? To me, The AS settings says something still insn't just right, but its really really close.
Looking for thoughts and suggestions! Thanks guys!
I took a lot of advice from here to get the Mikuni on my 2017 125sx to run properly. Different slide with a notch, different needle jet, all kinds of different jets and needles, holes in the float bowl, new seal and so on. I got it to run quite good, especially when I just accelerated hard from turn to turn. What was always not so nice is how the carb handled technical sections with on off throttle. It would load up and run inconsistently.
Now I had the chance to buy a 36 Keihin from a 125 EXC of ebay and what can I say... I took the jetting from the 2016 125SX (with the 38 Keihin) and the bike ran better and much more consistent from the get go than with everything I've tried with the Mikuni. It picks up great and just feels nice and smooth. It’s also less finicky with temperature differences (couldn’t test it in different elevations yet).
So if you've got the chance to get a Keihin and you’re not an expert on jetting Mikunis, buy it! It makes life so much easier.
Cheers!
Main jet 500
Pilot jet 32.5
Slide 5.75 (Kawasaki part#16025-0003)
Needle 43-75 (KTM part #55431134400)
Clip position #2
Needle jet S4 (KTM part #55431021400)
Air screw 1.5-2.0
Fuel 55:1
The Shop
Luxon 4-Post Bar Mounts
$189.95 - $239.95
DeCal Works Huge Plastic Inventory of UFO and Polisport kits.
450 main and mains up to 470
I’m running 50:1 Motorex with non ethanol 93 or T4
Currently jetting is the following, def rich and boggy. Temps are going up here in NC soon (80-90drg with 85%+ humidity…. Basically FL) so I wanna dial this jetting asap. Bike has 35hrs and I don’t race much just love to ride . Mostly track but some
Sprint enduro too requiring crisper low end.
Current jetting:
Stock 4.slow slide
MJ 430
NJ s1
JN is JD Blue on 2.5 clip
PJ 37.5
AS 1.5 out
PV 2in Yellow spring
I’m going to order parts based on knowledge gained from this invaluable thread AJ and so many have dialed. This is what’s in my cart to play with. The slide is the one thing that I’m bouncing between 5.0 and 5.5 I live in the 1/4-2/3 throttle range with MX and Sprint enduro… I’d love to find a setting where I’m just maybe dealing with AS and PJ adj between disciplines if feasible. Also interested in anyone running T2 exclusively and their jetting.
My Cart:
5.5 Slide
43-75 and 42-75 Needles
S4 NJ
480, 485, 490, 500 MJ
35 PJ (I have a 32.5 too already to play with)
Fresh silencer packing
JD Jet block kit
Question is , am I worrying too much about 1mm on the slide leaning it badly in unison with the S4 and needle swap? Everything above is moving in a lean direction other than the MJ which is honestly the least of my concern as I barely touch it.
My bike currently has the 5.75 slide with humid 100 degree weather.
Thanks for feedback!
Brandon🤙
AJ's specs (I got PV set differently but that's personal pref.
MJ 490
PJ 32.5
AS ~ 1.5 turns out
Needle jet S4
Needle 42-75 on the 2nd clip
Slide 5.5
Fuel mix 50:1
Runs crisp, clean, no bog.
I had a 19 TC250 with same setup minus a 5.0 slide as I couldn't get a 5.5.
It was running great too (full disclosure/ Slow Vet C level)
I would not worry about the slide but if you feel more comfortable doing so get a 5.0, try then re-cut it to 5.5
Once set, it's only A/S adjustment if the temp/humidity change radically
The TMX works fine...
Pit Row
Pump gas is loaded with ethanol here.
Itching to get these parts to get testing/tweaking! Should be a good weekend for it 70's and sunny here on the coast with humidity ~70%
Post a reply to: 125/150/250/300 KTM/HUS/GG jetting thread