We’re talking about a special ECU program here: push the button to select the mode, hold the throttle open, release the clutch, and the CRF250R will do the rest, launching you into the first turn with a big advantage. It turns your bike into a holeshot-seeking machine!
The CRF250R’s 79.0mm bore and short 50.9mm stroke let our engineers create a high-revving engine with plenty of room for large valves. The engine breathes and revs—the two keys to making power in the motocross world.
The CRF250R’s clutch uses two different types of friction material. Why? The clutch can handle the increased power of the engine without being any larger. The lighter rotating weight is directly related to how fast the engine revs. Stronger clutch springs help cope with all that power.
The CRF250R uses a double-overhead-cam (DOHC) engine layout with a unique finger-follower rocker design. Together with the rest of the engine’s architecture (bore and stroke, intake tract, piston, and more), you get more power and a higher redline.
The DOHC cylinder-head design let our engineers straighten out the CRF250R’s intake and exhaust tracts. The intake is short and just about arrow straight, and the exhaust flows more efficiently too. No athlete’s going to win a sprint if they try to run while holding their breath, and it’s no different with your bike’s engine. You’ll experience both more power and better throttle response.
The CRF250R’s dual-exhaust system is light, compact, and positioned close and low in the frame to take weight off the rear end and bring more mass to the bike’s center for improved handling. The pipes' length are fine-tuned to give you more low- and midrange torque.
This simple handlebar-mounted button lets you dial in engine power delivery character with a push of your thumb. Choose between Standard, Smooth and Aggressive, depending on track conditions.
Deep in the engine, there’s a special oil scavenge pump. While you may never see it, it helps keep the CRF250R’s overall design compact.
Talk about smart: The CRF250R features an ECU with special engine mapping for each gear. You can’t give an inch in this class, so having your engine deliver optimal power for each gear choice is one of the features that separates CRF250R riders from the rest.
Notice how the CRF250R’s dual exhaust pipes make gradual, large-radius bends out of the head, then flow straight back to the mufflers with no abrupt angle changes. Getting the exhaust out of the engine—while still maintaining a tuned exhaust length, is the key to power, while the pipes’ low mass and twin-silencer design optimize the CRF250R’s center of mass for superior handling.
Look closely at the CRF250R’s crankshaft profile and you’ll see its “H” cross-section design. What’s up with that? Just like a structural “I” beam in an aircraft wing or a skyscraper, it boosts strength and cuts weight over a conventional crank’s shape—a big deal when you consider this part spins at over 14,000 rpm!
Like the rest of the CRF250R, the bike’s Lithium-Ion battery is both super light and high performing. In fact, it weighs less than half the weight of a conventional lead-acid battery.
The 2021 CRF250R uses a shared engine/transmission oiling design. Why? Combining the two systems shaves weight and helps make the engine more compact, especially when it comes to placing the right-side cam drive and the clutch so close together.
Every gram counts on a bike in the 250 class, which is why the 2021 CRF250R has a titanium fuel tank. Light and strong, it’s also thinner than our previous plastic unit, freeing up more space and helping to centralize fuel mass.
Light is right when it comes to a high-revving engine’s reciprocating masses. That’s why the CRF250R uses titanium intake and exhaust valves. Plus, the valve angle is a super-narrow 20.5 degrees (included). Ovalized valve springs and long-wearing Diamond-Like Carbon (DLC) treated finger rockers complete the package.
Total air management means complete attention to how efficiently air gets through the intake, through the head, and out the exhaust. Eliminate losses here, and you make more power everywhere. And the best part? It’s free horsepower—you just need a bike with smart design.