| MODEL | YAMAHA DT 125E 1978 - 1979 |
| Year | 1978 - 1979 |
| Engine Type | Two stroke, single cylinder, reed-valve |
| Displacement / Capacity | 123 cc / 7.5 cu in |
| Bore X Stroke | 56 x 50 mm |
| Compression Ratio | 7.1:1 |
| Cooling System | Air cooled |
| Max Power | 9.5 kW / 13 hp @ 7000 rpm |
| Max Torque | 13.9 Nm / 1.4 kgf-m @ 6500 rpm |
| Ignition | Battery and coil (flywheel magneto charging, 12V 7Ah battery) |
| Induction | Single 24 mm Mikuni carburettor |
| Start System | Electric and kick |
| TRANSMISSION SPECS | |
| Lubrication | Autolube (1.2 Litres / 1.76 qts oil capacity) |
| Gear Box | 6 speed |
| Clutch | Wet multiplate |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | — |
| Front Suspension | Telescopic forks, 160 mm / 6.2 in travel |
| Rear Suspension | Monocross, 115 mm / 4.5 in travel |
| Front Brakes | Drum |
| Rear Brakes | Drum |
| DIMENSION SPECS | |
| Overall Length | 2030 mm / 79.9 in |
| Overall Width | 860 mm / 33.9 in |
| Overall Height | 1090 mm / 42.9 in |
| Seat Height | 820 mm / 32.3 in |
| Wheelbase | 1325 mm / 52.2 in |
| Ground Clearance | 250 mm / 9.8 in |
| Dry Weight | 104.5 kg / 230.3 lbs |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | 2.75-21 |
| Rear Tyre | 3.25-18 |
| FUEL SYSTEM | |
| Fuel Capacity | 7.0 Litres / 1.85 US gal |
| Fuel Consumption | — |
| Top Speed | — |
The DT125E added an electric starter to the Monocross DT125 as well as a kick lever, bringing a battery and a slightly heavier build. It kept the air-cooled six-speed two-stroke layout and drum brakes of the standard model.
