| Specification | Data Detail |
|---|---|
| Production Years | 2004 – 2017 |
| Engine Oil | Pro Honda GN4/HP4 SAE 10W-30 (JASO MA) |
| Oil Capacity (Engine) | 0.66 L (0.69 L with filter) |
| Transmission Fluid | 0.67 L |
| Spark Plug | NGK IMR8C-9H (Laser Iridium) |
| Tire Size (Front/Rear) | 80/100-21 51M / 100/100-18 59M |
| Battery | YTZ7S |
Engineering Highlight: A defining technical characteristic of the Honda CRF 250 X is its Unicam® valve train. While competitors often utilized heavier Dual Overhead Cam (DOHC) setups, Honda’s ME11 series utilized a single-cam configuration to actuate both intake and exhaust valves. This reduced the overall cylinder head weight and lowered the center of gravity, a critical factor in the machine’s legendary flickability in tight woods racing.
Technical Review: The ME11 Architecture
The Honda CRF 250 X (variants ME11A, ME11D, and ME13) represents the pinnacle of Honda’s carburetor-era enduro development. Unlike its motocross sibling (the CRF250R), the ‘X’ model was engineered with a wide-ratio transmission, a dedicated electric start system, and a more compliant suspension valving specifically tuned for off-road endurance rather than stadium jumps.
Lubrication System: Dual Sump Design
One of the most important maintenance aspects for the CRF 250 X is its split lubrication system. By separating the engine oil from the transmission oil, Honda ensured that clutch debris and transmission heat do not contaminate the sensitive top-end components. For the engine side, use SAE 10W-30 (JASO MA, Non-Moly). It is vital to avoid ‘Energy Conserving’ oils with friction modifiers (Moly) in the transmission side to prevent clutch slippage.
Ignition and Electrical
The ME11 series relies on a high-output ACG to power its lighting and charging system. The YTZ7S battery provides the cold cranking amps required for the electric starter, though the bike retains a kick-starter for emergency backups. For optimal combustion under high-heat off-road conditions, the NGK IMR8C-9H Laser Iridium plug is mandatory to maintain a consistent spark across the RPM range.
Maintenance Guide: Handling & Chassis
The chassis is a fourth-generation twin-spar aluminum frame. To maintain the intended handling characteristics, tire pressure is paramount. We recommend a baseline of 1.0 bar (15 psi) for both the 80/100-21 front and 100/100-18 rear tires. Lower pressures can be used for extreme mud or rock sections, but increase the risk of rim damage and pinch flats due to the bike’s 250cc torque profile.
Pro-Tip from the Editor
Always inspect the valve clearances every 15-20 hours of hard use. The intake valves, in particular, are known to tighten over time. Using high-quality fuel and keeping the air filter meticulously clean are the two most effective ways to extend the life of the Unicam® assembly.