A unique engineering highlight of the 2017 Honda CRF 250 RE (CRF250RE/17) is that it represents the final, most refined iteration of Honda’s proprietary Unicam engine design for the 250 class before the transition to DOHC in 2018. This specific model year perfected the dual-exhaust architecture, a design choice intended to centralize mass and improve flickability in tight corners, making it a favorite for technical motocross tracks.
| Quick Specs: Honda CRF 250 RE (2017) | |
|---|---|
| Engine Type | 249cc Liquid-Cooled Single-Cylinder (Unicam) |
| Engine Oil | Pro Honda GN4 SAE 10W-30 (0.71 L) |
| Spark Plug | NGK R0452A-10 |
| Battery | None (Capacitor system) |
| Tire Size (Front) | 80/100-21 51M |
| Tire Size (Rear) | 100/90-19 57M |
| Tire Pressure | 1.0 bar (15 psi) F/R |
Technical Overview: The Unicam Legacy
The 2017 CRF 250 RE is powered by a 249cc four-valve Unicam engine. By using a single overhead cam to actuate the intake valves directly and the exhaust valves via a forked roller rocker arm, Honda achieved the compact dimensions of a SOHC engine with the high-RPM performance characteristics of a DOHC setup. For the 2017 RE model, the engine mapping was refined to provide a more linear power delivery, particularly in the mid-to-high range.
Maintenance Guidelines
Lubrication System
Precision is key for the CRF250RE’s longevity. The system requires 0.71 Liters of Pro Honda GN4 SAE 10W-30 oil, meeting the JASO T 903 MA standard. Given the high-revving nature of this engine, oil changes should be frequent, especially under race conditions, to prevent thermal breakdown and shear.
Ignition and Electrical
Distinct from many modern dual-sport bikes, the 2017 CRF 250 RE features a capacitor-based electrical system rather than a lead-acid or lithium battery. This reduces weight and eliminates battery maintenance, though it requires a healthy kick to charge the capacitor for the PGM-FI system to initialize. The specified spark plug is the high-performance NGK R0452A-10, which must be gapped correctly to ensure consistent combustion under high compression.
Chassis and Traction
The 2017 model utilizes the 6th generation aluminum twin-spar frame. To maintain the intended handling geometry, tire pressures should be set to 1.0 bar (15 psi) for both the 80/100-21 front and 100/90-19 rear. This pressure provides the optimal contact patch for intermediate terrain while protecting the rims from impact.
Editor’s Verdict
The CRF250RE/17 remains a benchmark for riders who value lightweight handling and the unique power pulse of the Unicam engine. While it lacks the electric start found on later models, its mechanical purity and the absence of a battery make it one of the most reliable and ‘ready-to-race’ platforms in the used market today. Proper adherence to the 0.71L oil capacity and NGK plug specifications is mandatory to preserve its championship-winning pedigree.