After 12 years of dominating the 250F class, Yamaha enters 2027 with an all-new YZ250F engine design. Since introducing the fuel-injected, reverse-cylinder platform in 2014, the YZ250F has become the bike to beat, racking up shootout wins and professional championships along the way. With new FIM and AMA sound regulations on the horizon, Yamaha went back to the drawing board in an effort to keep its 250F powerplant at the top of the class while reducing overall noise. Did they actually make an already great engine better, or should they have just left it alone? We headed to the ClubMX Facility to find out.

Specifications

Engine

Chassis

Dimensions

To watch and hear our thoughts, click play. To read our thoughts, keep scrolling.

First Impressions

Well, to give you my true first impressions of this bike, you’d have to go back three or four years to when I was at Yamaha and we first started developing this machine. While it didn’t look nearly as fit and finished as it does now, the updated bodywork and engine were still noticeable changes. Early in development, I was a little worried because restricting sound usually does one thing: it costs power. The 450s were fine because they’re too fast anyway, but we definitely didn’t need to lose horsepower in the small-bore class. So, going into this intro, I still had some concerns based on what I remembered from riding the bike during development. Luckily, Yamaha still had another year or so to continue working on it before the production version was released.

Right away, I headed over to the perfectly groomed sand track and started ripping laps. I was slightly surprised by how easily I could use third gear in some of the faster turns. It didn’t take long to realize that although this was an all-new bike, it still maintained that great YZ250F feel. Even with the reduced noise, it honestly didn’t sound that much quieter while warming up. The tone is less raspy than before, but it’s still not the greatest-sounding bike. After a few laps, I knew I was in for a damn good day and was just hoping the heat and humidity didn’t kill this Cali kid too quickly.

Engine

Alright, this is what everyone’s really here for: Did Yamaha mess this engine up or not? Although we didn’t have a 2026 bike there to compare back-to-back, I can confidently say they didn’t mess it up. In fact, I think they improved it overall. One of the main complaints with the YZ in the past was that it felt flat up top and signed off quickly. Well, Yamaha increased the rev limit by 700 rpm, which some people might not think sounds like much, but on track, it feels like a big difference. This thing has much stronger top-end power, and the over-rev is longer and smoother, making it much more enjoyable to rev out. Before, you could hear the RPMs climbing, but the engine wasn’t really producing any additional power. Now, the increase in power matches the rise in RPM much better, making the bike easier and more rewarding to ride at high RPM.

Midrange power also feels stronger, but maybe not quite as exciting as before, as the higher rev limit gives the engine a slightly slower-revving character. Low-end power and torque are where I’m still on the fence, and I need to ride this bike back-to-back with the 2026 to give you a definitive answer. While it felt good, I could use third gear in corners, and throttle response was still strong, my suspicion is that the 2027 lost a little torque and initial response due to the new sound regulations. Even so, I believe it will still have some of the best low-end power and torque characteristics of any 250F in the class. The Power Tuner app continues to make tuning this engine easier than with any other manufacturer. I loaded a freer-feeling map that Yamaha’s testing department came up with, and while it helped the engine feel slightly freer-revving, I was still searching for more low-end response and power. Once we get our bike, I’ll work on a map and post it here.

The exhaust has also been improved and sounds less raspy compared to the ’26, but plenty of people still commented that it doesn’t have the best tone, and I’d have to agree. Now more than ever, I think an aftermarket exhaust is going to unlock additional power due to these new sound regulations. We had the opportunity to ride a GYTR kit bike equipped with an airbox and FMF exhaust system, and this was exactly what I was looking for. It’s also a relatively easy change. The combination increased low-end power and torque while also improving the mid-to-top, which made the engine even easier to control. I could also shift less thanks to the broader power character.

Overall, Yamaha once again has a great 250F engine that I think will still be very hard to beat in 2027.

Chassis

The 250F receives the same chassis updates that the 2026 YZ450F got. When we first started development, this chassis was pretty easy for us to work with because the Japanese test riders had already done a great job establishing a solid base setting. The updated chassis now has a calmer character through the bumps with improved overall comfort.

While chassis behavior isn’t quite as critical on a small-bore bike as it is on a 450, there’s still a noticeable difference compared to the 2026, and I think a lot of riders will appreciate the changes. There’s more front-end contact feel, which makes flat corners easier, and the front end feels more predictable with less of that twitchy character. That gives me more confidence to push harder.

ClubMX wasn’t at its roughest during our test day, so the differences weren’t massive in those conditions. However, I’ve ridden these chassis back-to-back before during the prototype stages, and I’m confident saying Yamaha improved the chassis overall. It still doesn’t have the stability of the 2022 chassis, but it’s improved, and Yamaha is taking steps in the right direction toward getting back to that stable, comfortable bike we loved. The bike also gained three pounds, but I honestly couldn’t feel the additional weight compared to what I remember from the previous model. We’ll confirm that once we get the opportunity to ride them back-to-back. Overall, it still has a lightweight feel and is easy to lean over and hold your angle through corners.

Suspension

This is normally where Yamaha has set the gold standard for production suspension for many, many years. The KYB and YZ combination is basically peanut butter and jelly. A new shock for 2027 makes that package even better, as it continues to offer excellent comfort and performance throughout the stroke. It has a progressive damping character with good hold-up, giving the bike a solid balance right out of the gate. The fork is where I had some issues with the YZ last year, and I felt a little bit of that again with this bike. The fork was decent overall, but it had somewhat of a mid-stroke stopping point and also felt slightly soft compared to the shock. On lighter-load bumps, the fork didn’t move through the mid-stroke as smoothly as I wanted and had a slightly harsh feel. Then, when I hit something hard, it would blow through the end of the stroke more easily than the shock.

I ended up going a couple of clicks stiffer on compression and opening the rebound two clicks, which helped, but I was still looking for a little more comfort from the fork to better match the shock. I then dropped the forks from 2mm above the clamps to flush, and that gave me the best overall feeling. It really helped high-load stability and gave the fork a little more comfort overall. It did make the initial part of cornering slightly more difficult when leaning in, but the tradeoff was a calmer and more stable bike.

Overall, though, this is still one of the best suspension packages available out of the box and should suit a wide range of riders.

Other Bits

A few other things stood out to me on the new bike, starting with the hydraulic clutch, which I’ve been pretty vocal about not being a huge fan of. On a 250F, though, it doesn’t bother me nearly as much. In fact, the slightly more on-off engagement can actually be a positive because it helps with RPM recovery. The YZ hydraulic clutch is also one of the better systems on the market, as it has a decent window between disengagement and engagement. I abused the shit out of this thing first thing in the morning on the sand track, and it held up well. There was a little bit of play after about 30 minutes of riding, but it wasn’t anything major.

I also kind of like the new bodywork around the side number plates with the black two-tone design. The front number plate, on the other hand, could use some work. We also really need to get some MX34s on this thing and move on from the discontinued MX33s. The handlebar pad is another item I’ve complained about since it debuted in 2023, and it needed to be changed yesterday. I don’t even know if this thing should be called a pad because there’s basically no cushion to it. If you smash into it, it’s not going to feel good. Change this thing ASAP when you buy your YZ.

The Final Word

So, at the end of the day, did Yamaha mess the YZ250F up? Not at all. They actually improved it in many ways and did a damn good job of keeping good power while meeting new sound regulations. A calmer, more stable chassis that’s easier to corner and ride overall makes this bike one of the top competitors to win the 250 shootouts this year. After twelve years on the same engine design that clearly was successful, Yamaha took a big risk with this engine, but I feel like it will pay off just fine for them, as we still have a great YZ250F machine.