| MODEL | HONDA CB 900C CUSTOM 1981 |
| Year | 1981 |
| Engine Type | Four stroke, transverse four cylinder, DOHC, 4 valves per cylinder |
| Displacement / Capacity | 901 cc / 54.9 cu in |
| Bore X Stroke | 64.5 x 69 mm |
| Compression Ratio | 8.8:1 |
| Cooling System | Air cooled |
| Max Power | 70.8 kW / 95 hp @ 9000 rpm |
| Max Torque | 77 Nm / 56.7 lb-ft @ 8000 rpm |
| Ignition | Inductive electronic |
| Induction | 4 x 32 mm Keihin carburettors |
| Start System | Electric |
| TRANSMISSION SPECS | |
| Lubrication | Wet sump |
| Gear Box | 5 Speed with two-range sub-transmission (10 ratios) |
| Clutch | — |
| Final Drive | Shaft |
| CHASSIS SPECS | |
| Frame | — |
| Front Suspension | 37 mm air-assisted fork, 155 mm / 6.0 in travel |
| Rear Suspension | Dual air-assisted shocks, 97 mm / 3.8 in travel |
| Front Brakes | 2 x 280 mm discs, 2 piston calipers |
| Rear Brakes | Single 297 mm disc, 1 piston caliper |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | — |
| Ground Clearance | — |
| Dry Weight | 277 kg / 611 lbs |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | 110/90-19 |
| Rear Tyre | 130/90-16 |
| FUEL SYSTEM | |
| Fuel Capacity | 16 Litres / 4.2 US gal |
| Fuel Consumption | 41.2 mpg (US) |
| Top Speed | 217.3 km/h / 135 mph |
The second-year CB900C continued with the same 901 cc shaft-drive four and ten-speed dual-range gearbox, with only cosmetic changes over 1980. It remained a heavy, comfortable cruiser-tourer suited more to relaxed highway work than hard cornering, with air-adjustable suspension and powerful triple disc brakes.
