| MODEL | NORTON MERCURY 1968 - 1970 |
| Year | 1968 - 1970 |
| Engine Type | Four-stroke, parallel twin |
| Displacement / Capacity | 646 cc / 39.4 cu in |
| Bore X Stroke | 68 x 89 mm |
| Compression Ratio | 9.0:1 |
| Cooling System | Air cooled |
| Max Power | 35 kW / 47 hp |
| Max Torque | — |
| Ignition | Coil capacitor |
| Induction | Single Amal concentric carburettor |
| Start System | Kick |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 4-speed |
| Clutch | — |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | Single downtube cradle |
| Front Suspension | Telescopic fork |
| Rear Suspension | Swingarm with plungers |
| Front Brakes | Drum, twin leading shoe |
| Rear Brakes | Drum |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | — |
| Ground Clearance | — |
| Dry Weight | 185 kg / 408 lbs |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | 3.00 x 19 rim |
| Rear Tyre | 3.50 x 19 rim |
| FUEL SYSTEM | |
| Fuel Capacity | — |
| Fuel Consumption | — |
| Top Speed | — |
The Mercury was the last of the old Dominator-style twins, a single-carburettor 650 sold after Norton Villiers took over AMC. It was assembled largely from leftover parts while the Commando took priority, so it is often described as a parts-bin special. It was essentially a milder one-carb 650SS with 12 V capacitor ignition.
