At the heart of the 1978 Yamaha DT 125 MX enduro - offroad motorcycle, Yamaha utilizes a 123 cc (7.5 cu in) air-cooled single cylinder, two-stroke layout. In factory specification, peak output is rated at 14 HP (10.2 kW) at 7,000 rpm while maximum torque reaches 9.8 Nm (7.2 lb-ft) at 6,500 rpm, transferring power to the rear wheel through a 6-speed gearbox and chain final drive. With a specific output of 113.8 HP per liter and a 500 rpm working window between peak torque (6,500 rpm) and peak power (7,000 rpm), the engine character is reflecting a performance-oriented street tune that balances strong mid-range pull with an energetic top-end rush.
On the scales, the DT 125 MX measures 102 kg (225 lbs) wet (curb), translating to a power-to-weight ratio of 0.14 HP/kg (7.29 kg per horsepower). Rider ergonomics and chassis geometry center around a 845 mm (33.3 in) seat height — resulting in a taller command-style riding posture suited to medium-to-tall inseams. The 7-liter (1.8 US gal) fuel tank supports practical everyday commuting and weekend road stints, while factory top speed is listed at 110 km/h (68 mph).
Specific Output
113.8 HP/L
Power-to-Weight
0.14 HP/kg (7.29 kg/HP)
Power Band Window
6,500–7,000 rpm
Standover Height
845 mm (33.3 in)
Engine
Displacement123.0 ccm (7.51 cubic inches)
Engine TypeSingle cylinder, two-stroke
Engine DetailsSingle cylinder, two-stroke
Power14.0 HP (10.2 kW)) @ 7000 RPM
Torque9.8 Nm (1.0 kgf-m or 7.2 ft.lbs) @ 6500 RPM
Bore x Stroke56.0 x 50.0 mm (2.2 x 2.0 inches)
Fuel SystemCarburettor. Mikuni VM 24 SH
Fuel ControlMembrane
LubricationAutolube
CoolingAir
Max RPM8000
Transmission
Gearbox6-speed
Final DriveChain (final drive)
Performance
Top Speed110.0 km/h (68.4 mph)
Chassis
Rake30.0°
Front SuspensionHydraulic telescopic fork
Front Travel180 mm (7.1 inches)
Rear SuspensionMonocross
Rear Travel145 mm (5.7 inches)
Ground Clearance265 mm (10.4 inches)
Wheels & Brakes
Front Tyre2.75-21
Rear Tyre3.00-18
Front BrakesExpanding brake (drum brake)
Front Brake Ø130 mm (5.1 inches)
Rear BrakesExpanding brake (drum brake)
Rear Brake Ø130 mm (5.1 inches)
Dimensions & Weight
Dry Weight95.0 kg (209.4 pounds)
Weight incl.102.0 kg (224.9 pounds)
Power/Weight0.1474 HP/kg
Seat Height845 mm (33.3 inches) If adjustable, lowest setting.
Use this page to compare this motorcycle by its real specifications, not only by model name. Focus on the details that affect fit, comfort, handling, range and ownership.
Power
Compare engine output with similar motorcycles if acceleration, highway use or two-up riding matters.
Torque
Torque is useful for judging real-world pull, especially for touring, commuting and loaded riding.
Seat Height
Check the seat height against your inseam and riding posture before choosing a motorcycle.
Weight
Compare weight carefully because it affects low-speed handling, parking and confidence.
Fuel Capacity
Fuel capacity helps estimate touring range and how often you may need to stop.
Brakes
Brake setup is worth comparing if you ride in traffic, mountains or with a passenger.
Suspension
Suspension details can matter for comfort, road feel and long-distance riding.
Transmission
Transmission and final drive affect maintenance, smoothness and everyday usability.
