In order to achieve their powerplant development goal of increased power (particularly at higher revs), engineers gave the 249cc engine an all-new dual-overhead-cam design, using a finger rocker arm with Diamond Like Coating (DLC). The titanium intake and exhaust valves are larger and have a higher lift and narrower angle, while the valve springs’ coils now have an oval cross-section to keep engine height as low as possible. The engine has more over-square dimensions, the cylinder offset has been increased, and the piston now features a bridge-box design–a first for a production Honda motocrosser. The intake system is now of a downdraft design for maximum efficiency, there are twin exhaust ports, and the dual exhaust features smoother routing and optimized pipe length. An electric starter is standard, powered by a small, lightweight lithium-iron phosphate battery. The end result of the copious changes is an engine with more power across the rev range, especially impressive at peak rpm.
The 2017 CRF450R set new standards for vehicle packaging in a motocross machine, with highly concentrated mass and a very low center of gravity; the 2018 CRF250R follows suit, with weight reduced overall but particularly up high and at the ends of the vehicle. A layout is slim and low, and the machine has superb rear-wheel traction but minimal front-end lift–ideal for strong starting and acceleration. The main spars of the new-generation, lighter aluminum frame are now tapered to optimize flex characteristics and provide good stability and reliable rider feedback, while a shorter wheelbase improves overall agility. An all-new titanium fuel tank and extruded subframe end save precious weight up high, a new Showa coil-spring fork contributes a plush suspension feel, and a lower, more centralized shock location improves stability. Bodywork mirrors the design of the CRF250R’s bigger brother in form and function, with a minimalist appearance and in-mold film graphics. Dunlop’s superb Geomax® MX3S tires are standard.
As a result of the engine and chassis updates, the 2018 CRF250R enjoys a three- percent improvement in start performance compared to its predecessor, along with improved acceleration and handling.
- More over-square bore/stroke dimensions
- Increased valve size/lift, narrower valve angle, oval cross-section valve springs
- Higher compression ratio
- Downdraft air intake
- Dual exhaust ports/headers/exhausts
- Electric start
- Lighter frame/subframe with optimized flexibility characteristics
- Revised chassis geometry for lighter handling, improved rear traction, reduced front-end lift
- Coil-spring fork
- Titanium fuel tank
ABOUT AMERICAN HONDA
American Honda Motor Co., Inc., is the sole distributor of Honda motorcycles, scooters, ATVs and Side-by-Sides in the U.S. American Honda’s Motorcycle Division conducts the sales, marketing and operational activities for these products through independent authorized Honda retail dealers. For more information on Honda products, go to powersports.honda.com.