A Buying Guide to the Best Non-Street-Legal 4-Stroke Dirt Bikes

Best non-street-legal 4-stroke dirt bike guide highlights:

• Many motorcycle manufacturers offer non-street-legal 4-stroke dirt bikes in a variety of engine capacities
• The best 250cc option is the Yamaha YZ250F, the best 350cc model is the KTM 350 SX-F, and the best 450cc bike is the Kawasaki KX 450
• If you prefer an electric motorcycle instead of a 4-stroke one, check out the KTM Freeride E-XC dirt bike

If you want a dirt bike that’s legally allowed on paved roads, a dual-sport model is your only real option. However, if you’re looking to escape civilization as much as possible, the dirt bike family’s other members are up for the task. And while 2-stroke models certainly have their advantages, if you’re new to the trail-riding world, a 4-stroke dirt bike offers more familiarity. Not to mention, depending on the manufacturer, more models to choose from.

But more choice is arguably a problem, too. It means deciding not just what kind of dirt-capable motorcycle you should get, but which model. However, to make picking out the right 4-stroke dirt bike easier, MotorBiscuit has made a handy guide to the best models on the market right now.

Best 250cc non-street-legal 4-stroke dirt bike: 2022 Yamaha YZ250F

The Ténéré 700 isn’t the only off-road-capable Yamaha motorcycle worth considering. Dirt Rider gave the 2021 Yamaha YZ250F in first place in its most recent 250cc motocross motorcycle comparison. Reviewers called it “the most well-rounded 250 four-stroke motocross bike you can buy.” So, if you want a 4-stroke dirt bike in the 250cc class, this is the one to get.

And for 2022, the best 250cc non-street-legal 4-stroke dirt bike is getting some extra tweaks. The 2022 Yamaha YZ250F has a new rear hub, rear sprocket, and chain, all of which are lighter and stronger, Dirt Rider reports. So, it has less unsprung rear weight, which improves handling and suspension performance. Its rear wheel has a stronger spoke design and a wider rim; also, the YZ250F rides on Dunlop Geomax MX33 tires instead of Bridgestone X20s. Plus, Yamaha revised the fork settings and improved the rear shock’s low-speed damping.

The outgoing Yamaha YZ250F already had an impressively-comfortable but still sharp ride. But the 2022 model somehow improves on that, offering incredible plushness without sacrificing sharpness or stability, Dirt Rider notes. And because the handlebar position is adjustable, it’s easy to find a ‘rider triangle’ that suits you. Also, as before, the bike has two-mode adjustable engine mapping, so you can tweak the performance for whatever track or trail you’re on. In short, the 2022 YZ250F “is a killer all-around package,” Dirt Rider says.

• Official classification: Motocross
• Factory warranty: 30-day/unlimited mileage
• Interesting feature: You can add additional engine maps, as well as tweak existing ones and monitor your YZ250F via the free Yamaha Power Tuner app—it’s like an ECU tuner for your smartphone
• Alternative choice: $9399 2022 KTM 250 SX-F; runner-up in Dirt Rider’s 250 Motocross Shootout, it’s a more aggressive, race-focused machine, but is less comfortable and has less low-end power and torque

Best 350cc non-street-legal 4-stroke dirt bike: 2022 KTM 350 SX-F

Austrian motorcycle brand KTM has made a strong name for itself in the off-road world, from adventure bikes all the way to motocross and trail bikes. And it has the best non-street-legal 4-stroke dirt bike in the 350cc class: the 2022 350 SX-F. Motocross Action went so far as to call the 2020 version “the best all-around midsize motocross bike.”

For 2022, KTM kept changes minimal on the 350 SX-F. A few engine parts were updated to improve response and durability, the suspension has some new linkage seals for better feedback, and the bike has new graphics. The rest of the bike—the Brembo brakes, traction and launch control, handlebar-mounted engine-map switch, and aluminum frame—is the same as it was on the updated-for-2020 model.

However, the KTM 350 SX-F didn’t necessarily need more significant tweaks. Being a 350cc 4-stroke, it’s a great dirt bike for those who want more power out of a 250cc but think “a 450 is too much bike,” Dirt Rider muses. And the “progressive powerband” helps the rider make the most out of the “awe-inspiring handling” and excellent ergonomics, Motocross Action notes. In short, this middleweight all-arounder is worth “serious consideration” regardless of where and how you ride, Dirt Rider says.

• Official classification: Motocross
• Factory warranty: 30-day/unlimited mileage
• Interesting feature: You can easily remove the air filter without tools and customize the airbox around specific track conditions and desired engine dynamics
• Alternative choice: $10,199 2022 Husqvarna FC 350; virtually identical mechanically (as many Huskies are) to the KTM, it has softer suspension settings, which make it comfier but also more unsettled over certain jumps  

Best 450cc non-street-legal 4-stroke dirt bike: 2022 Kawasaki KX 450

The reborn KLR 650 is big news for off-road Kawasaki fans, but the Japanese brand has more to offer. In addition to the KLR and its ATV/UTV lineup, Kawasaki also has many 2-stroke and 4-stroke dirt bikes. And with a third-time first-place finish in Dirt Rider’s recent 450 Motocross Shootout, Kawasaki’s flagship MX model, KX 450 is the best 4-stroke dirt bike in the 450cc segment.

The 2022 Kawasaki KX 450 is mechanically identical to the updated 2021 version. However, there’s now a Special Racing model inspired by the brand’s race bikes. And the $12,399 2022 KX 450SR gets a few upgrades besides the Monster Energy-style graphics package.

Firstly, the 2022 Kawasaki KX 450SR has polished intake ports, a titanium race exhaust, and a new ECU mapping. So, it’s lighter and more powerful than the standard model. Also, the 450SR has KYB suspension, with new 0.3” more front travel, new rear linkage, and diamond-like carbon and Kashima coatings to reduce friction and smooth action. Plus, the triple-clamp and handlebars have new mounts. Finally, the 450SR rides on stronger D.I.D. DirtStar ST-X rims.

Still, you don’t need the SR to have a fun time in the dirt on the Kawasaki KX 450. It’s a comfortable, agile, maneuverable, 4-stroke dirt bike with “a user-friendly engine [that’s] controllable and predictable,” Dirt Rider says. Hence why it’s the best choice for 450cc riders.

• Official classification: Motocross
• Factory warranty: None
• Interesting feature: All KX 450 models have launch control and Kawasaki’s Ergo-Fit system of adjustable seats, handlebars, and levers
• Alternative choice: $9599 2022 Yamaha YZ450F; the second-place finisher in Dirt Rider’s 2021 450 Motocross Shootout, the 2022 model has new suspension settings, less unsprung weight, and standard ECU-remapping capability

Best electric alternative: 2022 KTM Freeride E-XC

While this guide is about the best 4-stroke dirt bikes, electric models are starting to hit the market. And while not all of them are street-legal, they offer performance on-par with their internal-combustion-powered counterparts. Plus, you don’t need to master a clutch lever to ride them.

If that sounds appealing to you, the best choice for a non-street-legal electric dirt bike is the KTM Freeride E-XC. It doesn’t have adjustable ECU mapping, it does have three riding modes that adjust the top speed and power output. And unlike many non-street-legal dirt bikes, 4-stroke and otherwise, the E-XC has some instrumentation. Specifically, a digital display with a speedometer, warning lights, and charge indicator.

KTM upgraded the Freeride E-XC’s brakes in 2021, following a 2018 update that added new suspension, battery hardware, and regenerative braking. As a result of these changes, the 2022 model is “an all-around fun bike” that’s less of a play-toy and more of a serious trail machine, Dirt Rider says. And racers like Andy Lagzdins are starting to modify E-XCs for genuine competitions, Dirt Rider adds. Also, because it’s electric, the Freeride E-XC has more low-end torque, though top-end power could use an upgrade.

Still, if you want the dirt bike experience but want something cleaner than a 4-stroke, a KTM Freeride E-XC is a solid alternative.

• Official classification: Trail
• Factory warranty: 30-day (overall), 36-month (battery and charger)/unlimited mileage
• Interesting feature: It has a swappable battery pack if you don’t want to wait 110 minutes using the external 230-amp charger
• Alternative choice: $13,000 Cake Kalk OR; with 15 hp, it’s less powerful than the E-XC, but it has Ohlins suspension and only weighs 152 lbs

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