| MODEL | HARLEY-DAVIDSON RR-250 ROAD RACER 1974 |
| Year | 1974 |
| Engine Type | Two-stroke, parallel twin |
| Displacement / Capacity | 246 cc / 15.0 cu in |
| Bore X Stroke | 56 x 50 mm |
| Compression Ratio | 12.0:1 |
| Cooling System | Liquid cooled |
| Max Power | — |
| Max Torque | — |
| Ignition | — |
| Induction | — |
| Start System | — |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 6 Speed |
| Clutch | — |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | Steel tube |
| Front Suspension | 34 mm Ceriani telescopic fork |
| Rear Suspension | Twin Girling shocks |
| Front Brakes | — |
| Rear Brakes | — |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | 1250 mm / 49 in |
| Ground Clearance | — |
| Dry Weight | — |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | — |
| Rear Tyre | — |
| FUEL SYSTEM | |
| Fuel Capacity | 19 Litres / 5.0 US gal |
| Fuel Consumption | — |
| Top Speed | over 209 km/h / 130 mph |
The RR-250 was the two-stroke twin road racer built at Harley-Davidson's Aermacchi factory in Varese, Italy, for 250 cc Grand Prix racing. In 1974 Walter Villa won Harley-Davidson's first world road-racing championship on it, then won again in 1975 and 1976, adding the 1976 350 cc title on the related RR-350. The 1974 bike used the water-cooled version of the engine with a six-speed gearbox and Ceriani forks.
