| MODEL | HONDA CR 450R 1981 |
| Year | 1981 |
| Engine Type | Two stroke, single cylinder, reed valve |
| Displacement / Capacity | 431 cc / 26.3 cu in |
| Bore X Stroke | 85 x 76 mm |
| Compression Ratio | 7.1:1 |
| Cooling System | Air cooled |
| Max Power | 39.4 kW / 52.9 hp @ 6500 rpm |
| Max Torque | 57.7 Nm / 42.6 lb-ft @ 6000 rpm |
| Ignition | CDI |
| Induction | Single 38 mm Keihin flat-slide carburettor |
| Start System | Kick |
| TRANSMISSION SPECS | |
| Lubrication | Pre-mix |
| Gear Box | 4-speed |
| Clutch | Wet plate |
| Final Drive | #520 chain, 14T / 54T |
| CHASSIS SPECS | |
| Frame | Chrome-moly steel |
| Front Suspension | 41 mm Showa air-adjustable fork, 305 mm / 12.0 in travel |
| Rear Suspension | Pro-Link, 312 mm / 12.3 in travel |
| Front Brakes | Drum |
| Rear Brakes | Drum |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | 950 mm / 37.4 in |
| Wheelbase | 1508 mm / 59.4 in |
| Ground Clearance | 325 mm / 12.8 in |
| Dry Weight | 104 kg / 229.2 lbs |
| Wet Weight | 113 kg / 248 lbs |
| WHEEL SPECS | |
| Front Tyre | 3.00-21 |
| Rear Tyre | 5.10-18 |
| FUEL SYSTEM | |
| Fuel Capacity | 9 Litres / 2.38 US gal |
| Fuel Consumption | — |
| Top Speed | — |
The CR450R was Honda's open-class motocross bike for 1981 only, an air-cooled two-stroke single with a four-speed gearbox. It was among the first Hondas to use the Pro-Link rising-rate rear suspension, paired with air-adjustable Showa forks and drum brakes at both ends. It was replaced the following year by the larger CR480R.
