MXA RACE TEST: THE REAL TEST OF THE 2025 KAWASAKI KX450 SPECIAL RACER

THE GEAR: Jersey: Moose Agroid, Pants: Moose Agroid, Helmet: Arai VX-Pro4, Goggles: Viral Brand Signature, Boots: Alpinestars Tech 10.

Q: FIRST AND FOREMOST, IS THE 2025 KAWASAKI KX450 SPECIAL RACER BETTER THAN THE 2024 KAWASAKI KX450SR?

A: Yes, by default, it’s eons better than the 2024 KX450SR because Kawasaki didn’t make a Special Racer model in 2024. The Special Racer was first introduced in 2022 as a modified version of the KX450; only, it came with Kayaba suspension instead of Showa, which has been OEM on Kawasaki’s 450 models for a while. The KX450SR returned for 2023 but with coated Showa suspension instead. Last year, Kawasaki spent all their time and energy developing the new engine and frame, so they focused their resources on that model, putting the “Special Racer” on hold for a year. 

Q: WHAT DIFFERENTIATES THE 2025 KAWASAKI KX450SR FROM THE STOCK 2025 KX450?

A: The 2025 KX450 retails for $10,499, while the Special Racer costs $13,599. Here’s the list of parts that bring on the $3100 upcharge. 

(1) Forks. The Showa spring forks have dark Kashima-coated uppers and titanium-oxide-coated lower fork legs. The upper fork legs create a hard, low-friction surface, helping to prevent damage to the inside of the tubes. The coating on the lower fork legs also makes for a stronger surface that protects against wear and rock dings. The SR forks utilize larger 39mm compression damping pistons and 25mm cartridge cylinders, providing smooth action and firm damping. The forks also have dedicated valve settings and an extra 4cc of oil in each fork to create a more racy suspension setup than the stock bike. 

(2) Shock. To match the forks, there is dedicated SR valving in the shock, and the outer shock body is Kashima-coated, while the shock shaft is not coated and is the same diameter as stock.

(3) Engine. The KX450SR comes with polished intake ports to optimize airflow on its way into the engine. It also has a metallic magnesium gold head, but it’s hard to notice it. 

(4) Pro Circuit. Like the factory Kawasaki team, the KX450SR has a full Pro Circuit Ti-6 titanium exhaust system. This boosts power, drops weight by 1.5 pounds and makes the bike sound like a real racer. This specific muffler was made by Pro Circuit in conjunction with Kawasaki, and it was built specifically to work with the 450SR’s ECU and intake polishing. The header is the same as what Pro Circuit sells, but if you want this exact muffler, you must purchase it from a Kawasaki dealer. Of course, Pro Circuit sells its own version of the KX450 muffler as well, which is different internally and has a larger exhaust outlet (35mm on KX450SR muffler and 42mm on the standard Pro Circuit muffler). 

(5) ECU. The electronic control unit map settings have been tailored specifically for this bike to work with the polished intake ports and Pro Circuit exhaust. It is also inherently different from the stock bike. With the stock KX450, the “light off” is the stock map, while “light on” is the mellow version of the stock map. On the SR, “light off” is stock and “light on” is a more aggressive version of the stock map. The mapping can also be adjusted on the KX Rideology app as well. 

(6) Drive chain. The KX450SR comes with a black Renthal rear 50-tooth sprocket and a gold D.I.D chain.

(7) Triple clamps. The Special Racer comes with Xtrig’s ROCS-tech triple clamps with opposite clamping for improved fork grip. It also comes with Xtrig’s PHDS bar mounts, which are taller than stock and reduce vibration.

(8) Wheels. The stock bike comes with non-branded D.I.D rims, while the Special Racer comes with D.I.D’s ST-X rims. 

(9) Aesthetics. The KX450SR has a stock clutch with a Hinson clutch cover. It also has race-team-inspired graphics, only this time it’s missing the Monster logos. Kawasaki explained that they wanted more “Special Racer” branding for 2025, but we’re guessing Monster didn’t offer any incentive for Kawasaki to include them on the OEM graphics. It also has a green Renthal bar pad.

Q: HOW DOES THE 2025 KAWASAKI KX450 SPECIAL RACER RUN ON THE TRACK?

A: We like this engine because it is the only factory edition available with an engine that’s more exciting than the stock offering. Comparatively, Honda’s CRF450 Works Edition engine is also better than Honda’s stock CRF450, but it’s not more aggressive than the stocker. If anything, the CRF450WE feels smoother than the stock engine, because it fills in the dips in the stock power curve and offers linear power. 

The KTM, Husqvarna and GasGas Factory Editions don’t come with any engine work, and their ECU mapping is the same (albeit they are adjustable via smartphone on the Factory Editions). The Austrian bikes also run the stock header, with either an FMF (GasGas/Husky) or Akrapovic (KTM) muffler on them. Thus, the engine character is very close to the stock bikes for those brands. 

Switching back to the Green Machine, the stock 2025 Kawasaki KX450 engine is extremely mellow. Even though it peaks at 58 horsepower on the dyno, the manner in which the power is made feels sluggish compared to the other brands. Therefore, we are extra thankful that Kawasaki took big swings at improving power for their Special Racer edition. 

The KX450SR engine is much more exciting than the stock KX450.

The 2025 KX450SR engine is all about low-to-mid power. Compared to the stock engine, it is much more exciting down low and  stronger in the middle, but it doesn’t pull any further on top. Riding the stock bike back to back against the KX450SR highlighted how much stronger the KX450SR was in the low end. The stock KX450 is a second-gear motorcycle, and we’re glad that the KX450SR is strong enough to pull third in most corners (except for the tighter ones).

MXA has two other KX450s to compare with the Special Racer: (1) stock KX450 (2) a KX450 with a Twisted Development-tuned Vortex ECU and Pro Circuit Ti-6 exhaust system. The

Twisted-tuned KX450 proved how much room for improvement the Special Racer still has on over-rev.  

When compared to the CRF450 Works Edition, the KX450SR was deceiving. A less experienced rider might think the KX450SR it’s faster because of how loud the Pro Circuit exhaust is and how much the KX450SR vibrates, but in reality, it was slower. The CRF450 Works Edition is smoother, has a more connected throttle to rear-wheel feel, less of a hit, less vibration and is much quieter. 

Q: HOW IS THE 2025 KAWASAKI KX450 SPECIAL RACER’S NEW ECU MAPPING?

A: The SR’s ECU is very impressive for a stock ECU straight from the factory, but it shouldn’t be compared to a Vortex ECU. With the stock KX450SR black box, you’re forced to stay within the stock parameters (Kawasaki’s preferred safe range). Of course, the tunable range is limited. The Vortex ECU expands the rpm range, giving you that extra 1000 rpm that our test riders were looking for. We have over 50 hours on our Vortex-equipped KX450 and Pro Circuit exhaust-equipped models, and we haven’t had any issues, even though the Vortex ECU pushes Kawasaki’s parameters further than Kawasaki wants to sell their bike with. We also don’t like that you can’t change maps in motion. You have to shift into neutral to go from map one to map two on the KX450SR. 

Traction control works well. With the solid light on, it has the least influence, while the blinking green light setting initiates detuned settings for traction control. If the track is slick, we like the first TC setting with the solid light. However, in no conditions did we think the blinking green light setting was necessary. This bike doesn’t have enough power to give up what the blinking light detunes. Also, Kawasaki has a smartphone app now—KX Rideology—but we aren’t big fans of it. You can customize the mapping, but we couldn’t find anything better than the stock setting with the light on.

At $13,599, the KX450SR is the most expensive 450 on the market.

Q: HOW DOES THE 2025 KAWASAKI KX450SR HANDLE ON THE TRACK?

A: Kawasaki’s new frame came with a 1-degree-steeper head angle in 2024 to make it more nimble and improve the KX450’s turn-in prowess. However, when you combine the steeper head angle with soft, vet-friendly suspension settings, the stock 2024–’25 KX450s tend to oversteer and exhibit head-shake at speed—something we never complained about on the 2023-and-prior-model KX450s. Thanks to stiffer suspension settings and Xtrig triple clamps, the 2025 Kawasaki KX450SR doesn’t have those issues. The stiffer valving and extra 4cc of oil in each fork leg increased hold-up throughout the fork’s stroke, alleviating the head-shake and oversteer quibbles that bothered us on the stocker. 

At the same time, the 2025 KX450SR did lose the comfort that we’ve long been accustomed to with the KX450 platform. Even though the spring rates are the same, the Special Racer suspension is much stiffer and racer-oriented. The front end chatters any time you encounter acceleration bumps, causing our test riders to lose confidence in the front end. It’s surprising how different the KX450SR and standard KX450 are in the handling department. We’ve called the stock model a couch, but the KX450SR is not so. 

Of course, the stiffer valving and extra oil play their part, but triple clamps also play a role in the front-end character. After all, they are the ligament that connects the front wheel and front end to the rest of the chassis. Xtrig clamps have been known to be on the stiffer side in the past, so we decided to trade them out for Ride Engineering’s new KX450 clamps for comparison. Right away, our test riders noticed a 20-percent improvement in comfort. It was a revelation we weren’t expecting! Does this mean the Xtrig clamps are bad? Not necessarily; they just offer a different feel. Some riders like the stronger “hand feel” that comes with the Xtrig clamps, because it gives them a better feel for the track (meaning you can feel the bumps in your hands more). However, our test riders found it was much easier to find comfort with Ride Engineering’s triple clamps, and no turn-in performance was lost in the process. 

We should note that the Xtrig clamps did help slightly with vibration. They didn’t resolve vibration entirely; it still vibrates more than any other 450 four-stroke when you’re high in the rpm range, but the PHDS (Progressive Handlebar Damping System) did absorb some vibration, which we liked.

The Showa forks are set-up as racer’s suspension, plain and simple. They are not comfortable like the stock KX450, but it allows you to go faster.

Q: HOW IS THE 2025 KAWASAKI KX450 SPECIAL RACER’S SUSPENSION?

A: It’s a racer’s suspension, plain and simple. It’s not comfortable like the stock KX450, but it allows you to go faster. For our intermediate and pro test riders, the suspension works well coming into turns because they come in hotter and are heavier on the brakes than our vet test riders, but even our faster test riders were struggling to find comfort in acceleration chop. 

To help with the oversteer and head-shake issues on the box-stock KX450, our test riders lengthened the chain by two links (the stock chain is 114 links; we lengthened it to 116). Even though the SR suspension alleviated those issues for us, we tried lengthening the chain on the Special Racer also. However, when the wheelbase got longer, the fork felt harsher in the flush position in the clamps. So, we slid the forks from the flush position to 2mm to get more weight on the front end. From there, we went two clickers stiffer on one fork leg and one click stiffer on the other—crazy, right? While it’s true these Showa forks are sensitive, not every test rider could feel this minuscule change, but one of our lead test riders felt this was the go-to setting. 

One thing that’s tough about the new KX450 is adjusting the shock. The high- and low-speed compression adjuster fits tightly between the frame and side number plate, but that’s not our complaint. We find it frustrating that adjusting the preload on the shock is so difficult. As a manufacturer, you want your customers to ride with the proper sag setting to ensure they’re happy with the suspension. But, if it’s a pain to access the shock preload adjuster, the average rider won’t want to check it as often. Plus, the linkage gets in the way of the rebound adjuster at the bottom of the shock. You have to take the bike off the stand and put weight on the seat to get a flat-bladed screwdriver in there. 

Q: WHAT IS THE 2025 KAWASAKI KX450SR MISSING?

A: The Kawasaki KX450 Special Racer comes with a lot of great stuff on it, but it’s missing some key items. First, we wish it had a gripper seat cover. With a $13,599 price tag and the word “racer” in the name, the bike should come with a gripper seat cover. Gripper seats help you stay in the proper position, they prevent arm pump and save you energy. With a slippery seat, when you get on the throttle, your butt slides back. The only way to prevent sliding is to grip harder, which makes you tired quicker and gives you arm pump, or give it less throttle, which means you’re going slower and having less fun.

We think every modern 450 should come with a gripper seat. One more gripe about the seat: Kawasaki is the only brand that still has sharp corners on their seat. We’d prefer rounded edges like the factory Kawasaki riders have on their bikes. 

In the same breath as the seat, we think the Special Racer needs to come with a holeshot device. If you’re a serious racer, you need one. The KTM, Husky and GasGas Factory Editions come with holeshot devices, so Honda and Kawasaki should both take note. 

We also wish the KX450 came with a Twin Air Powerflow kit. When Kawasaki came out with their 2024 KX450, they made their air filter smaller, and they closed off airflow to the filter to lower the decibel output in order to meet the stricter European FIM regulations for 2025 and beyond. We hate the KX’s slide-in air filter system and the two-piece air filter cage. It doesn’t seal very well, and it’s a pain to try and put a new filter on the two-piece cage. We installed a Twin Air Powerflow kit, even though it’s not simple to initially install because it replaces the base plate. It makes for a much more confidence-inspiring seal for the filter. We also took Pro Circuit’s advice and removed the extra plastic surrounding the filter as much as possible with a Dremel to boost airflow and wake the engine up. 

Finally, we wish the KX450SR came with a full Hinson clutch. The Honda CRF450 comes with the Hinson setup and we love it. It helps justify the price, because installing a clutch basket is one of the more challenging upgrades you can make to a bike. Grinding the primary gear off the back of the stock clutch basket is not for the faint of heart. 

Q: IS THE KX450SR WORTH THE EXTRA MONEY?

A: The answer to this question will be different for different riders. The KX450SR mapping is specifically tailored for this bike. It’s way better than stock mapping, but it’s not as good as a Twisted Development Vortex ECU. With our Vortex-tuned KX450, Twisted could raise the rev limiter and boost over-rev power. If you were going to take your stock ECU to Twisted Development for a remap, it would cost $350, plus you’d be without an ECU for at least a couple of days. To buy a new Vortex ECU and have Twisted give you 10 different map options, it’ll cost $1050. 

Calculating the suspension cost is more complicated. Of course, if you sent it to a tuner, they would set it for your size and skill level. However, if you were to send off your suspension to be coated, that would cost a couple thousand dollars and would keep you off the bike for a longer time. Suspension gurus will readily admit that the only true Kashima coatings are done in Japan. There are other less expensive options, but they aren’t the same quality. The over-the-counter price for this suspension is expensive, but the best part of it is the convenience factor because if you buy the KX450SR, you don’t need to send your forks out to be coated. Without the coatings, a re-valved fork and shock might be around $800, depending on who you choose. 

When it comes to putting the aftermarket triple clamps on your stock KX450, if you were to buy the Xtrig ROCS (Revolutionary Opposing Clamp System) triple clamps with the PHDS bar mounts, it would set you back $800. However, our test riders weren’t the biggest fans of these with the stock suspension on this bike. 

The polished intake port on the cylinder head certainly does something, but we’ve never taken a stock 450 four-stroke and had just the intake port polished before; it’s not worth the hassle. We’d rather spend the money on a complete head-porting job or an aftermarket piston or cam. As for the Pro Circuit Ti-6 exhaust, that retails for $1400. 

Adding it up, if you took your stock KX450 and added a remapped stock ECU, Pro Circuit exhaust, suspension re-valve and Xtrig clamps, it would add an extra $3350 to the bike, and that’s not counting the coatings or the polished intake.

Q: WHAT DID WE HATE?

A: The hate list.

(1) Missing parts. It needs a gripper seat cover and a holeshot device to live up to its name. 

(2) Shock. You really have to cram your tools in there to adjust the preload and rebound.

(3) Plastics. The plastic is brittle and cracks easily. Fox Raceway isn’t known for being rocky, but we lost the top of our fork guard on a practice day—and the fork guard had thick graphics on it, too. Usually, the aftermarket fork guard graphics help hold it together, but not this time. 

(4) Seat bolt. The T-plates that attach the 10mm seat bolts to the rear fender fall out easily. We ordered Bolt Hardware’s replacement T-plates, which are built to stay in place. 

(5) Threads. The 8mm bolt on the left-side number plate, which has to be removed every time you change an air filter, strips easier than any other bolt-in motocross. 

(6) Spokes. It would be nice if they used the same spoke nipple size, front and rear, to make maintenance checks simpler.

(7) Airbox. We hate the new KX450 airbox; replace it with a Twin Air Powerflow kit. 

(8) Vibration. The stock KX450 vibrates, and so does the KX450SR. The Xtrig bar mounts help, but they don’t solve the problem.

(9) Price. At $13,599, this is a very expensive machine.

We never thought that any of the Big Four would be brave enough to spec a Brembo front brake. Kawasaki was and we love it.

Q: WHAT DID WE LIKE?

A: The like list.

(1) Package deal. If you were already planning to get these mods, the KX450SR saves you time and money. 

(2) Chain slider. Thankfully, Kawasaki replaced their unreliable chain roller with a simple chain pad that can’t fall apart. 

(3) Engine. We’re thankful Kawasaki added some oomph to the SR edition. We wish the stock bike ran like this. 

(4) Suspension. The coatings look cool and help promote fluid action with the forks and shock. 

(5) Xtrig. The stock bar mounts twist easily. Most aftermarket bar mounts fix this.

(6) Grips. We are always thankful for the ODI lock-on grips. Kawasaki used to vulcanize their grips to the handlebars.

(7) Ergos. This is the only bike with adjustable footpegs. They can be lowered 5mm for taller riders. 

(8) Brembo. We love the Brembo front brake.

Q: WHAT DID WE REALLY THINK OF THE 2025 KAWASAKI KX450SR?

A: At the end of the day, it might be smarter to buy a stock KX450, especially if the dealerships are offering massive rebates like they did last year, and spend the money saved on your own favorite products. You can tune the suspension specifically for you and buy the aftermarket exhaust of your choice. We don’t have big issues with the stock KX450 triple clamps (only the stock bar mounts), so the Xtrig clamps didn’t sweeten the deal all that much for us this year. However, our test riders are quick to say that this bike is a package deal. If you’d rather ride than tinker on your bike, then you’ll appreciate all these mods that come pre-installed from the factory. Yes, the KX450SR is much better than the 2025 Kawasaki KX450, but it’s not as exciting for us as the 2022 and 2023 KX450SR models were.  Beware of roost when riding a Kawasaki. The stock fork guards break easily and leave your expensive, coated, lower fork legs vulnerable.