| MODEL | AJS 7R RACER BOY 1957 - 1961 |
| Year | 1957 - 1961 |
| Engine Type | Single-cylinder four-stroke, single overhead camshaft, chain-driven |
| Displacement / Capacity | 349.2 cc |
| Bore X Stroke | 75.5 mm x 78 mm |
| Compression Ratio | 12:1 |
| Cooling System | Air |
| Max Power | 27.6 kW / 37 hp @ 7600 rpm |
| Max Torque | — |
| Ignition | Lucas magneto |
| Induction | — |
| Start System | — |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 4-speed, separate |
| Clutch | — |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | Duplex cradle with single top tube |
| Front Suspension | AMC Teledraulic telescopic fork |
| Rear Suspension | Pivoting fork with Girling hydraulically damped units |
| Front Brakes | Drum |
| Rear Brakes | Drum |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | — |
| Ground Clearance | — |
| Dry Weight | 129 kg / 285 lb |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | — |
| Rear Tyre | — |
| FUEL SYSTEM | |
| Fuel Capacity | — |
| Fuel Consumption | — |
| Top Speed | About 185 km/h / 115 mph |
The 7R, called the Boy Racer, was AMC's over-the-counter 350 cc racing single, sold from 1948 and refined with a short-stroke engine and duplex frame by the late 1950s. By 1961 it was one of a handful of British production racers, built in small numbers and a staple of Junior class club and Manx Grand Prix racing.
