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Only $10 for all 2026 SX, MX, and SMX series.
For the 125, Slide #5 is what you want. They do go out of stock at JD Jetting but come back in stock regularly.
Slide 5 https://jdjetting.com/product/jdmk02-mikuni-tmx-ktm-husq-carburetor-sli…
Jet Block gasket https://jdjetting.com/product/jdmk05-mikuni-tmx-jet-block-kit/
S4 Needle Jet KTM PN 55431021400
YZ125 6BFY 42-74 needle Yamaha PN 284-14116-H4-00
Mans & pilots, buy OEM Yamaha or KTM, whichever is cheaper.
The Shop
Luxon 4-Post Bar Mounts
$189.95 - $239.95
DeCal Works Huge Plastic Inventory of UFO and Polisport kits.
I always like to experiment so I know what is what. If the 500 main feels good. go to a 510.. and then a 520.. keep going richer until you find the point of too much.. then back it off to the sweet spot. Same for the needle clip. Clip-2 might be good at the higher tracks but clip-3 might be better at Washougal. Only one way to really know.
I routinely run 37.5 pilot, clip-3 and big mains like 540-560 when the temps drop, but I am running AvGas which leans everything out.
Oh, I don't know if extra oil will help the 2022 crank probs. but 40:1 is plenty with Super-M under normal circumstances, at least me flogging my 2021 tells me so.. lol
I actually did notice some ongoing plating wear in my 5.5 slide so for next seasong im going to either file/machine my original or get an 5.0 as anything bigger is hard to get in here...
Engines running upwards of 11K RPM should be running 20-30:1 oil ratio (20 is better than 30 ALWAYS--> zero downside) and you need to run an oil that offers good protection at these higher RPM. This is critical!!
If you are searching for more power , cooler running engines, and longer bearing and piston life.... OIL will get you there.. Less oil= LESS life and less power.. and vice versa.
As you lower RPM (usually increase bore and stroke engines) you can lower the oil ratio (if you want) .I would never suggest EVER running less than 50:1 in ANY engine..
The idea that more oil , significantly, effects jetting is simply not accurate.. Switching from 50:1 to 32:1, for example, will not have any significant (read need to adjust jets) effect on jetting calibration.. I know.. Blasphemy... right?? but, true none the less..
currently I ride on a 125 TC 2017 with original settings
Main jet 480
Jet slows down 45
needles 43-74
s1
bushel 4.0
I only ride on ground temperature 5 degrees to 15 degrees at 100m elevation and the bike gouges at low speeds when the grip is fully open.
Do you have any recommended settings?
I'll be back to let you know as soon as I have everything installed
Pit Row
So I made the full adjustments from the front page and tested it in the motocross field today, the bike no longer chokes when the grip is open, but when stationary it gets rich and stalled, I'm thinking of changing the idle jet from a smaller one
40:1
Temperature 12 degrees in the morning and 25 in the afternoon altitude 0
The air screw I tried 1.5 and 2 turns it was always too rich
FMF factory line
as indicated the only modifications I made are the needle on the 3rd notch, and the jet slowed down to 35
the motorcycle has a hole in the net opening of the handle
otherwise RAS and correct color spark plug
Motor just rebuilt, nothing crazy done to it.
FMF exhaust with turbine core silencer.
I'm going to put the 36mm keihin carb on it.
Any jetting recommendations to start with?
SoCal riding conditions.
Thanks
Do These run any better with your jetting configuration?
Post a reply to: 125/150/250/300 KTM/HUS/GG jetting thread