| MODEL | HONDA CB 450K3 1970 |
| Year | 1970 |
| Engine Type | Four stroke, parallel twin, DOHC, 2 valves per cylinder |
| Displacement / Capacity | 445 cc / 27.1 cu in |
| Bore X Stroke | 70 x 57.8 mm |
| Compression Ratio | 9.0:1 |
| Cooling System | Air cooled |
| Max Power | 32.8 kW / 45 hp @ 9000 rpm |
| Max Torque | 37.4 Nm / 27.6 lb-ft @ 7000 rpm |
| Ignition | Coil with auto-advance, twin contact breakers |
| Induction | 2x 32 mm Keihin carburettors |
| Start System | Kick |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 5 speed |
| Clutch | — |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | Tubular semi-duplex cradle with single front down-tube |
| Front Suspension | Telescopic forks with two-way damping |
| Rear Suspension | Swing arm, shock absorbers with adjustable preload |
| Front Brakes | Single disc |
| Rear Brakes | Drum |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | 1300 mm / 53 in |
| Ground Clearance | — |
| Dry Weight | 187 kg / 412 lbs |
| Wet Weight | 204 kg / 449.7 lbs |
| WHEEL SPECS | |
| Front Tyre | 3.25-19 |
| Rear Tyre | 3.50-18 |
| FUEL SYSTEM | |
| Fuel Capacity | 14 Litres / 3.7 US gal |
| Fuel Consumption | — |
| Top Speed | — |
The K3 was the first CB450 to get a hydraulic front disc brake, paired with a larger 19-inch front wheel. Honda also restyled the silencers, fitted a bigger tail light and offered new colours. Contemporary road tests praised the brake, handling and comfort, a clear improvement on the troubled first-year bikes.
