YZ450f to feel like KTM350?

Check this out : https://youtu.be/MsJrtPo70xg?si=wQscPcsJQRmbDxIQ

is there anyway to turn my 2025 350 SXf into a 450… asking for a friend 🙃

366 big bore, flywheel weight and an ecu.

If you wanna build a perfect motor. I helped a buddy build this.

366 big bore, stroker crank wth matching pro rod, ecu and twisted exhaust flange. I forget what size he went to on his bike. I just told Phil at crank works to give him a crank that would put it back in line with the stock 350 ratio and to make sure no spacer plates would be needed. Not that I thought the stroke would be that much more. And we had the bowl on the head cleaned up to better match the piston. 

That bike fuckin ripped still handled like a 350 but had quite a bit more from crack to full throttle and only lost about 500rpm in over Rev compared to his 350. That was by far my favorite 350-450 motor I have ever ridden in a modern 4 stroke.

 If ktm built a true 400 they would never sell another 350 or 450 unless your race demands outright power like say flat track. Shit a 400 with a 450 top end in the power parts catalog would take care of everything 90% of us want or need.

Saddest part about this bike was the motor only lasted 18hrs. Rock to the right case and it was all gone before he knew what happened.

Uhh I don’t think that would be a good idea

I've been itching to try a 450 again. I rode my buddies '24 KX450. I'll take my 350 all day. I know Kawi's are not even the horsepower kings but it was still too much bike for me. I do think he had motor work done to it. I feel way more aggressive and nimble on my 350. Admittedly didn't ride the 450 much. Did a quick moto but was ready to get back on my bike 

With all the options for KYB suspension on the Austrian 350's, I don't see nearly as much benefit to the Yamaha.  Yes, the suspension set up is $$$, but the end result bike is nearly perfect.  You can make the current model 350s into just about any set up you can think of.  Want a little more power?  Get an exhaust, ECU, and use the air box cover with holes.  Want the plush KYB suspension, just order it and put it on.  Fantastic machines.  Super fun to ride.

It just depends on your style. But yeah what you described was a 18k$ 350. Exhaust ecu and kyb on top of a high dollar entry price for the 350 itself.

Vs a Yamaha that would need springs to suit?

Ktms are really good but it’s such a shame they keep beating this horse of making wp something it isn’t. Spec some kyb copies already and stop letting their egos get in the way of the product.

You're pretty much right. I do see a lot of guys who don't have no issues with the air fork. To be fair, I'm not one of them lol. I've got converted KYB's. I just have no need for a 450 anymore. Riding that Kawi this week just made my mind up even more. And the Yamaha has more motor than the Kawi. If I ever wanted to get off the KTM platform, it would be dropping down to a 250. A 450 isn't in the cards for me anymore