Honda CR250M
The Honda CR250M Elsinore revolutionized off-road motorcycling in the early 1970s by blending motocross performance with street-legal versatility. Its lightweight two-stroke powerplant and nimble chassis delivered race-inspired thrills beyond the track. Riders found the Elsinore equally at home tearing through trails or cruising paved roads, thanks to its compliant suspension and reliable engineering. This model set a benchmark for dual-purpose machines and remains a celebrated classic today.
Historical Background
Origins of the Elsinore Name
Honda introduced the CR250M in 1973, naming it after the famed Lake Elsinore Grand Prix in California where the company scored its first motocross victory. This race-winning pedigree infused the production bike with competitive DNA. By offering motocross performance in a street-legal package, Honda tapped into a burgeoning market of weekend adventurers craving off-road excitement without trailer hassles.
Evolution Through the Years
Over its brief production run, the CR250M saw incremental refinements to suspension damping, frame geometry, and brake hardware. Early ’73 models featured a steel cradle frame, while later ’74–’76 editions received stiffer tubes and revised mounting points for improved handling. Cosmetic updates included new tank graphics and color schemes, but the core engine and transmission layout remained a testament to Honda’s commitment to durability.
Engine and Powertrain
Two-Stroke Engine Design
At its heart, the CR250M sports a 246 cc air-cooled, single-cylinder two-stroke engine with rotary valve induction. The aluminum piston and nickel-plated cylinder bore reduce reciprocating mass for crisp throttle response. A compression ratio of 9.3 : 1 strikes a balance between power output and rideability, delivering roughly 30 hp at 7,500 rpm in stock tune.
Induction and Exhaust
Fuel metering relies on a 31 mm Keihin carburetor with a pilot jet circuit for smooth low-speed running. The engine breathes through a rotary disc valve, optimizing port timing for both torque and top-end surge. A tapered expansion chamber exhaust enhances powerband width, while a reverse-cone silencer tames noise levels to meet street regulations.
Transmission and Clutch
Power passes through a five-speed constant-mesh gearbox, offering closely spaced ratios ideal for both trail climbs and open stretches. A wet multi-plate clutch engages with light lever effort yet resists fade under repeated launches. Chain final drive with a splined aluminum rear sprocket ensures efficient, low-maintenance operation.
Chassis and Suspension
Frame Construction
The CR250M’s backbone is a duplex steel cradle frame engineered for torsional rigidity and controlled flex under load. Tubular sections are gusseted at stress points to withstand hard landings and aggressive cornering. This design delivers precise steering feel while preserving rider confidence on unpredictable terrain.
Front Suspension
Up front, a 36 mm telescopic fork offers 160 mm of travel, calibrated for compliant damping over rocks and roots. Chrome-plated fork tubes resist corrosion and provide smooth action throughout the stroke. Preload is fixed, reflecting the era’s focus on simplicity and reliability.
Rear Suspension
The dual-shock rear setup features adjustable preload on 5-way settings and 140 mm of travel. Lightweight aluminum alloy shocks dampen rebound and compression forces, soaking up jumps and washboards with minimal bottoming. The swingarm’s slim profile enhances rider mobility and feedback.
Brakes and Wheels
Braking System
At the front, a 260 mm ventilated disc brake with a twin-piston caliper delivers strong stopping power and good modulation. The rear relies on a sealed 158 mm drum brake, offering predictable feel under load. Brake lines and cables are routed to minimize snagging on trails.
Wheel and Tire Setup
The CR250M rolls on a 21-inch front wheel and an 18-inch rear, matching motocross conventions of the era. Rims are steel-spoked with aluminum hubs for a balance of strength and weight savings. Tires of 3.00–21 front and 4.00–18 rear dimensions provide a generous contact patch for traction in loose and hard-packed conditions.
Electrical and Lighting
A compact 12 V electrical system powers a Halogen headlamp, amber turn signals, and a tail/stop lamp. Ignition duties fall to a transistorized magneto, delivering reliable spark at high engine speeds without a battery dependency. The wiring harness is straightforward, enabling easy repairs and accessory additions.
Performance and Handling
The CR250M’s lightweight package of approximately 102 kg (dry) makes it exceptionally flickable on tight trails. Its broad two-stroke powerband rewards precise throttle control, while the chassis balances agility with stability at speed. Top cruising speeds of around 140 km/h are achievable on open roads, and the suspension soaks jumps with composure.
Maintenance and Service
Routine upkeep for the Elsinore is straightforward, thanks to its mechanical simplicity. Key service intervals include:
- Air filter cleaning after every off-road ride
- Engine oil inspection and gearbox oil change every 10 hours
- Spark plug inspection every 20 hours
- Expansion chamber and silencer inspection every 30 hours
- Chain lubrication and tension check every 5 hours
Periodic ring and port inspections keep the two-stroke engine performing at its peak.
Technical Specifications
| Specification | Detail |
|---|---|
| Engine Displacement | 246 cc |
| Engine Type | Air-cooled, two-stroke, single-cylinder |
| Bore × Stroke | 72 mm × 60 mm |
| Compression Ratio | 9.3 : 1 |
| Induction | Rotary valve, Keihin 31 mm carburetor |
| Ignition | Transistorized magneto |
| Transmission | 5-speed constant mesh |
| Final Drive | Sealed O-ring chain |
| Frame | Duplex steel cradle |
| Front Suspension | 36 mm telescopic fork, 160 mm travel |
| Rear Suspension | Dual shocks, adjustable preload, 140 mm travel |
| Front Brake | 260 mm disc, twin-piston caliper |
| Rear Brake | 158 mm drum |
| Front Tire | 3.00–21 |
| Rear Tire | 4.00–18 |
| Wheel Size | 21 in front / 18 in rear |
| Seat Height | 945 mm |
| Wheelbase | 1,455 mm |
| Dry Weight | 102 kg |
| Fuel Capacity | 9.2 L |
| Top Speed | ~140 km/h |
Conclusion
The Honda CR250M Elsinore blends motocross pedigree with dual-purpose practicality in an iconic ’70s package. Its spirited two-stroke engine, agile chassis, and manageable ergonomics made it a favorite among trail riders and enthusiasts alike. Decades later, the Elsinore’s blend of reliability and performance continues to inspire restorations, vintage rides, and a lasting legacy in off-road motorcycling history.
