2018 Honda CRF250R

2018 Honda CRF250R – A Completely New DOHC Engine, Electric Start and Return to Spring Forks

The 2018 Honda CRF250R marked one of the biggest transformations in the model's history. Honda abandoned the long-established Unicam engine architecture in favour of an entirely new double-overhead-camshaft design, introduced electric starting as standard equipment and replaced the previous Showa pneumatic forks with conventional coil-spring suspension. Combined with a new seventh-generation aluminium frame, the changes created a substantially different motorcycle from the 2017 CRF250R.

The new engine was developed with a clear emphasis on high-rpm performance, drawing heavily on Honda's experience in international MX2 competition. Although displacement remained 249.4 cc, bore and stroke changed dramatically from 76.8 x 53.8 mm to 79.0 x 50.9 mm. The larger bore and shorter stroke permitted larger valves and supported higher engine speeds. Compression increased to 13.9:1, while the cylinder was offset by 4.5 mm to help reduce internal friction.

The redesigned cylinder head incorporated two overhead camshafts operating four titanium valves. Intake valve diameter increased to 33 mm and exhaust valve diameter to 26 mm. Honda also revised the intake ports, combustion chamber and exhaust arrangement to improve airflow at high engine speeds. The result was a substantial increase in peak power, with Honda claiming approximately nine percent more maximum output compared with the previous model. The useful high-rpm power range was extended, and the engine's redline increased by approximately 900 rpm.

The new performance characteristics changed how the CRF250R delivered its power. Earlier Unicam machines were known for accessible midrange response, whereas the 2018 engine encouraged riders to maintain higher rpm and use the five-speed gearbox more actively. Experienced racers could exploit the stronger top-end performance on fast circuits and when accelerating towards jumps, although the revised power delivery required a different riding approach in slower sections.

Honda retained electronic PGM-FI fuel injection and the handlebar-mounted Engine Mode Select Button. Riders could choose between three fuel-injection and ignition maps to suit changing track conditions. The twin-muffler exhaust system also continued, but the exhaust layout was redesigned around the new cylinder head and engine configuration. Owners investigating replacement components should be aware that many engine, exhaust and electrical parts are not interchangeable with those of the previous generation.

Electric starting was another important milestone. The 2018 CRF250R became the first production CRF250R motocross model equipped with an electric starter as standard. A lightweight lithium-ion battery supplied the starting system, eliminating the need for the traditional kickstarter. This improved convenience after a stall or during difficult race conditions, although it also introduced additional electrical components requiring maintenance and diagnosis.

The chassis redesign followed Honda's mass-centralisation philosophy, using a seventh-generation aluminium twin-spar frame closely related to the contemporary CRF450R. Revised frame geometry, a lighter aluminium subframe and redesigned swingarm helped optimise rigidity, traction and steering response. A lightweight titanium fuel tank reduced mass high in the chassis, while the revised radiator positioning, narrower bodywork and flatter seating arrangement improved rider movement.

The suspension change was especially significant. Honda discontinued the Showa SFF-TAC pneumatic forks used between 2015 and 2017 and introduced 49 mm Showa coil-spring cartridge forks. The new suspension returned to conventional mechanical springs while retaining extensive compression and rebound damping adjustment. This simplified some aspects of ownership by eliminating the need to monitor multiple pneumatic spring chambers. Correct fork oil capacities and servicing procedures remained essential, particularly because the fork uses separate damper and outer-chamber oil quantities.

At the rear, Honda revised the Pro-Link suspension arrangement and repositioned the Showa shock to suit the new chassis. The motorcycle retained hydraulic disc brakes, with a 260 mm front rotor and 240 mm rear rotor. Dunlop Geomax MX3S tyres were fitted as original equipment, using the familiar 21-inch front and 19-inch rear wheel combination. These changes helped bring the suspension and braking package into line with the demands of the more powerful engine.

For owners and restorers, one of the most important mechanical differences is the lubrication system. Previous CRF250R models used separate engine and transmission oil compartments, but the 2018 DOHC engine adopted a common oil supply for both. The combined system requires approximately 1.12 litres after draining and replacing the oil filter. Following an older CRF250R service procedure could therefore result in incorrect oil servicing. Owners should always use the maintenance instructions specifically written for the 2018 generation.

Regular servicing remains vital because the CRF250R is a high-performance competition motorcycle. The engine's titanium valves, high compression ratio and increased operating speeds place considerable importance on clean oil, effective air filtration and scheduled valve-clearance inspection. The MXOwners motocross replacement parts finder can assist with researching compatible maintenance parts. During a chassis inspection, the motorcycle bearing finder provides another starting point for identifying wheel, steering-head and suspension-linkage bearings.

The 2018 Honda CRF250R established a new direction for Honda's 250 cc four-stroke motocross range.