picking a new bike is hard.

It's really not that hard. If you care about a dealer network then pick one of their bikes, otherwise pick a color. 

If you’re looking at a 250 four stroke just do yourself a favor and go with the YZ250f. Its got the best suspension off the showroom floor and a fantastic engine. Its a great bike. If you go with a KTM you’re gonna be constantly fighting your suspension til you send it out and have a KYB conversion done. My opinion is just avoid all the nonsense and get a Yamaha. 

This comment will get lots of down votes, but get a Stark, as much or as little power as you want, it's a smoother easier to ride bike, and uses the same suspension as your YZ250.

Ktms are naturally much more metered and linear delivery on all of their bike sizes compared to the yz450. A function of their throttle bodies and engine designs.

Tough to say whether you should go with Ktm or yz. I’ve done a ton of reflecting on the Ktm chassis I spent like 4 seasons on them, and I LOVED them at times and other times HATED them.

Depending how the track shaped up, how rough it was, how square edged it was, how whatever factor was different the bike just would be different. And it drove me nuts chasing settings and feelings and got downright not fun at times!

Now that I’m on a kawi, I know I wasn’t crazy! It was something with the bike/me not gelling in certain days and conditions.

Looking back, I actually think the bike needed a linkage and revalve around the linkage. It would just feel like I hit a landmine at times when hitting a bump I wasn’t even concerned about, but then the reaction would be 50x what my eyes were seeing out there.

I’d be riding and on the verge of arm pump and feel like i wasnt even pushing 70% , and im like what’s going on?! My buddies would all ride into the sunset and I’d feel like I was on the limit because of set up/feedback into my body, but skill wise and mentally I knew I wasn’t close to my ceiling.

This is a really long way to say, if you go Ktm, I wouldn’t be surprised if you should go for a well designed linkage, fork conversion, etc and spend the money there. Because the rest of the bike is so damn good, if the chassis and suspension would just be consistently what you need it to be the bikes are unbelievable.

The engines are amazing, the clutches last seemingly infinitely, the brakes are perfect, airbox design amazing etc etc.

 but dang did it have me questioning riding on many days because of how far off I’d feel one day to the next on them.
 

I don’t believe you said your skill level but I’ll assume you’re average b/c guy. 

First off the three bikes you mentioned are all great bikes. Depending on how much money you want to spend I’d do the 350 and do a spring conversion. Another bike to look into is the kx450. It’s the bike I have. Very easy to ride and you never feel out of control power like some of the other 450s. For me, as a vet guy we like to be lazy and the 250s require you to run the dog shit pit of them to go fast: 

Don’t the KTM XC’s come with springs now? Get a 350xcf

I think a 350 will feel more similar in power to your 250 2t but the 350 will be smoother/easier to ride. The 350 will pull a lot further if you let it. You will have to make the 250f scream. You have to accept that or you are not going to like a 250f. 

If you have the means to spend $1100 bucks on a vortex ECU, go with the 2023 or newer yz450f (all said and done might be cheaper than any new ktm). I have one on my 23, there is 10 maps to choose from and I use the linear map. It is so much damn fun and easy to ride. The suspension is great out of the box as well. I am 6' 4" 200 pounds and I run haven't touched the suspension. Just overall a great bike. 

I was in a similar position. Long time 2T diehard. My one experience with a 4T was horrible (older CRF250F). I went with a 24 KTM 350 SFX. I really like this bike! Enough power to not feel limited, but not overwhelming. 

Yes, just go this route. 

SXF tank is $110 if the bigger but same width tank bother you, 18" rear is fine unless you are really really fast and will notice it, or buy a spare 19" rear wheel. 

I agree 100% and couldn’t have said it better myself. I know none of us are Chase Sexton, but there’s something to be said when a guy with factory suspension tuners can look amazing one race then look totally uncomfortable the next. Its very well documented that the KTM brands biggest negative is the suspension. There are countless threads out there with people discussing the exact same issues and it’s pretty mind boggling KTM can’t seem to resolve it. Wait til Yamaha announces their electric start YZ250x for 2026. KTM will be hurting even more than they already are. 

I think in the case of the YZ250F, it's actually easier to scream that bike than a 350. The way the YZF revs, with that instant come to life feeling, is so easy to ride. I feel like the 350s you are getting a longer geared feel from the bike and each gear makes the bike feel very different. The YZF has a lot more overlap in the gearing. That being said, you still have to shift the bike a lot, and that's where the work comes in on the YZF. On a 350 you can basically just go back and forth between 2nd and 3rd around most tracks, but I feel like it's easier to feel like you are in the "wrong" gear, if that makes sense. 3rd on those bikes seem like it pulls so far and it's very fast though. But I don't think the YZF is harder to ride at all, just my opinion. 

I would probably cut the choice down to the 350 or the YZF. I personally feel like the KTM 250F has a very similar type of power to the 350, just less of it. So if you like that type of power, then just get the 350. The YZF on the other hand is almost the opposite in the way it runs. It's more about the response, recovery and fast revs. But you will be in 4th in a lot of sections that you wouldn't need 4th on a 350 or 2stroke. So much of it is personal preference and where you ride. It's tough to say. Also, factor in suspension. I also like the idea that someone mentioned about the new Kawi 450. 

x3

Have you thought about a new KTM 300sx?  The motor is super easy to ride but will have more power than your YZ.  Its like a 3 stroke as it has bottom end torque like a 4 stroke but revs out and feels lighter like a 2 stroke. 

He said he wanted more time on the track. Stark has a limited range.   

1st gear on the XCF is lower, 2nd through 4th are almost identical as the SXF then you also have a 6th gear on the XCF. 

Rode a yz250 for about 10 years, got the stroke itch, went with a 19 450sxf, rode that 5 years, now on a 24 fc350, never been happier, enough power, love the lower seat, even like the suspension, disclaimer I'm 61 and slow

Why buy new when there’s very low hr 04 cr125 s out there.  Best handling mod the engine for c12.  The most fun your going to hv 

I recommend you ride as many bikes as you can. I've demo'd Yamahas and KTM's in the last 10 years. I bet Stark has demos also. 

I suspect you will like them all, just a matter of preference. Enjoy!

Some are ok with the air fork some are not. If you ride one make sure the outer chambers get bled before riding. It doesn't take much air buildup to make them feel harsh.

It just boggles the mind that people are saying the stock KTM suspension is unrideable for the average guy to the point where you must do a spring conversion. I know a guy who raced a Canadian national on bone stock KTM suspension. 

The 250f will feel slow compared to your YZ. The 350 is, I think, quite comparable - it feels much more linear and smooth, but I found that on a start straight, it's actually considerably faster since you can hold it wide open and it'll keep pulling forever. You may wish you had more power with the 250. I doubt that you'll wish for more with the 350. The only guys I know who don't like the 350 are A class guys racing against 450s in the sand. That being said, if you're not racing, the 250f is a lot of fun. 

I have a 2000 cr250 and last year rode a 19 yz250 and on the same day rode a I think a 22 yz250f, I was surprised at how hard you had to work the 250f out of the corners compared to even my old cr.  

He said...

"want a smoother easier to ride bike, since I ride mostly hard pack tracks and want to be on the track longer"

He wants smoother power because he's tiring out.

You don’t need a KYB conversion but it is a great option. I know Ride JBI can do wonders with a WP 6500 cartridge kit that drops right in. Costs less than CV and KYB. I’d still go YZ though because I’ve ridden YZ250F and KTM 350 SX-F and I liked them both but the KTM is a little rich for my blood. I would still have the suspension done regardless of choice and with the money you save on the Yamaha get a Vortex ECU/Airbox mod from Twisted. Maybe a pipe too.

Hmm that's tough. How's your dealer network? You might just choose the best dealer.

The easiest transition will be the Yamaha 250F. KTM's - I don't know if you've ridden any - have quite different geometry. Not bad, just different. Same with the air forks. They're not bad, I wouldn't worry about them, but the Yamaha KYB forks are really good.

Power will be different regardless. 250F is easy to ride and IMO plenty fast. 350F has more grunt and less shifting but I doubt my lap times would be any faster. None of those are bad choices.