| MODEL | YAMAHA IT 425 1980 |
| Year | 1980 |
| Engine Type | Two stroke, single cylinder, reed valve |
| Displacement / Capacity | 425 cc / 25.9 cu in |
| Bore X Stroke | 85 x 75 mm |
| Compression Ratio | 7.3:1 |
| Cooling System | Air cooled |
| Max Power | 27.5 kW / 36.9 hp @ 6000 rpm |
| Max Torque | 31 lb-ft / 4.23 kg-m @ 5500 rpm |
| Ignition | CDI |
| Induction | 38 mm Mikuni VM38SS carburettor |
| Start System | Kick |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 5 Speed |
| Clutch | Wet, multi-plate |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | Triangulated rear frame with single monoshock damper |
| Front Suspension | 43 mm telescopic adjustable forks, 250 mm / 9.8 in travel |
| Rear Suspension | Monoshock, adjustable spring preload and rebound damping, 250 mm / 9.8 in travel |
| Front Brakes | Drum |
| Rear Brakes | Drum |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | 1430 mm / 56.2 in |
| Ground Clearance | 285 mm / 11.2 in |
| Dry Weight | 111 kg / 244.7 lbs |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | 3.00 -21 |
| Rear Tyre | 150/80 -18 |
| FUEL SYSTEM | |
| Fuel Capacity | 13.6 Litres / 3.5 US gal |
| Fuel Consumption | — |
| Top Speed | — |
The IT 425 was a one-year bored-out big-single enduro model for 1980, bridging the IT 400 and the later IT 465. It combined a 43 mm fork with long-travel monoshock suspension and a larger fuel tank.
