2023 Ktm 125SX

Pretty much All the new gen 125’s are having issues, there’s a thread on here somewhere that exposes a lot of the issues but I know from a fast local ripper wiring harness, ecu and cyclometer issues amongst the 4 new bikes he had, he has since sold them and moved to 4 strokes. 

Replating is the way to go 99% of the time anyway IMO. I’d get the ecu remapped while you are at it. No way you should be replacing a cyl and 25 hrs. Unless you sucked dirt or had a bearing/ ring/ piston failure. 

Is it a KYMCO cylinder?

No elko is what they are using on the 125's they were also back to using elko. On the 23 250/300's that had cylinders cracking the water jacket

Pretty sweet that KTM had new 2024s in the dealers months ago but still have TONS of customers waiting on backordered parts for '23s.

Ok just trying to catch up.  So the Elco cylinder is bad thought it was the Kymco lol

The piston should still be good but changing a top end on a 125 at 25 hours is sort of common if the bike is ridden very hard. 

My 21 150sx 18 hrs first top end from brand new elko cylinder. Porous spot on bottom edge of the intake skirt. Left a nice spot on the piston when it flaked off. Also a lil crap Porous spot in the oring groove.  The kymco cylinder on my 21 250sx at 50 hrs was much better. 

Had none of that porous crap, the elko is like rougher texture too. Like grainy almost. 

 I really was wanting a gasgas 125 with a carb.  no one had any, looked at the ktm's and heard about the parts issues ect. ended up with a blue bike and couldn't be happier.  I would try to replate your cylinder if you can. 

Ready to race... until you can't race because KTM has no parts available lol. 

Do you know anyone going to Loretta's? I'd bet they have a couple of those cylinders on the KTM rig out there. 

I would not touch the new 2 strokes from Austria. One guy I know that race pro that has had 4 250s sidelined after breaking down within 15h. Some after 2-3h. Failed rods, bearings, cylinders, pistons. 

It's a shit show apparently. Austria handles it on goodwill, but, bike letting go in the air is no fun. Never mind the bikes being unable to be ridden while waiting for parts and goodwill clearance. 

Crap I wanted to trade in my 18 sx 125 this year for a 23. Seems like I should wait for the 24

Get a YZ125

We got (2) of the '23 125's when they were very first released.  The very first day my son made me call the dealer and tell them the bike was not right.  KTM told us we were crazy.  Other riders told us we were crazy.  Every media outlet accept MXA told us we were crazy and there were no issues with the bike.  MXA admitted to having the same results my son described to them.  Luckily our dealer finally realized we knew our stuff and had our backs.  We had the bikes for 2 months and traded both in for 250F's.

The entire package needs major work to be competitive.  I had to buy a new cylinder for both bikes.  One bike blew up at 6 hours and the other at 21 hours.  Didn't have time to wait around for them to decide on warranty because we had races coming up so had to buy both of the cylinders.  The bike with 21 hours blew up because i had top end kits on back order... 

Long story short that bike was a nightmare for the 2 months we ran it...  Tell your son to run the YZ125 and go back orange when he's ready to go with a 250F.  Or just go ahead and go with a 250F.

We have a 20 and a 22 125sx. Both have been rock solid under hard use, albeit with very good maintenance schedule. 25 hours is all I get out of pistons under a fast rider. I've heard lots of horror stories about the 23s (early 22s had them too with crank failures) and my dealer insider said don't buy one. I do know some shops (TSP for one) are coming out with ECU mods and other fixes for the from-factory performance issues some are having with the 23. Who knows how the 24 will be, but I'm not taking the chance. KTM has screwed up this platform pretty badly IMHO.

Almost completely unchanged for 24, I’d try to find a leftover 22’. 

"24" is basically BNG 

So awesome how folks in the media who ride and report on these bikes don't say shit.

I've heard nothing but bad news about all of the FI models locally, which forced my hand into picking up a new YZ250 over a KTM 300. I've owned every brand except Austrian and they almost had me with that 300...

Can the new FI models be converted back to carb? 

Wow, that’s too bad on the 125s. Hopefully it’s just the cylinders that are bad. I’m guessing that includes Husqvarna and GasGas too. I wonder if it’s all 2-strokes or just the 125s

All the horror stories about the TBI bikes made me keep my 21 TC125 and run out and buy a 23 MC250 when the rebates dropped.  Carb love  !!!!!!!   

This exactly our scenario as well. Found one gas gas 14 hours away and went blue. Husky and KTM screwed the pooch with the new two strokes. We had a 23 TC 125 for approximately 4hrs. That was long enough to figure out it ran rich with a bog that couldn’t be fixed (and yes we had all the updates) Amazingly the YZ could be re jetted and made to run like a top. 

Noticed the same thing, I call them out on their social media and many agree. They are still buying into the hype of the TBI IMO

The 300's run great, at least the two I know of. Mine has 51 hours and has been flawless. Just got word my vortex top end showed up so I'll be doing a piston next week. My buddy has around 20 hours on his and not a single issue either. I rode another member on here's 22 yz250 last Saturday, good running bike but I cannot believe how much those things vibrate, it blew my mind. My 300 was also way faster and way easier to go fast on for me. Sucks that they shit the bed so hard on the 125's, I've been eyeing getting a 125 again and it'll either be a gas gas or YZ there for sure. I wouldn't hesitate to get a 300's.

Well I sure hope your 300 was faster than your buds YZ250 😂. Seriously though, glad you did the 300.  We’ve heard the same things about the 300 and 250 having very few issues. Kinda feel like the engineers were worried about the new 125s blowing up so they made sure that wouldn’t happen. Unfortunately they probably did as much damage to their reputation either way. 

I am hoping for MXA to provide a video or article on long term use of the new KTM 2 strokes. 

I have 3 125s, a spare motor, and lots of extra parts if anyone's interested - fire sale type deals to be had.  Lol.  We went YZ after 6mo of frustration with the KTM.  Wish we'd made the decision earlier - the YZ runs very well across the entire RPM range, unlike the KTM which we could never get to run right.

oh there is: https://motocrossactionmag.com/test-update-2023-ktm-125sx-two-stroke-a-…