These are the known mechanical and performance specifications for your 1970 Balkan MK50 2JU25.
Basic Specs

Engine
Displacement49.00 ccm (2.99 cubic inches)
Type
DetailsSingle cylinder, two-stroke
Max RPM
Compression9.0:1
Bore/Stroke40.0 x 39.0 mm (1.6 x 1.5 inches)
Valves/Cylinder
FuelingCarburettor
Ignition
Exhaust
Lubrication
CoolingAir
Performance
Horespower3.30 HP (2.4 kW)
Torque
Top Speed65.0 km/h (40.4 mph)
Fuel Economy & Polution
Fuel Consumption2.20 litres/100 km (45.5 km/l or 106.92 mpg)
Fuel Capacity
Emissions51.0 CO2 g/km. (CO2 - Carbon dioxide emission)
Chassis
Frame Type
Rake
Trail
Front Suspension
Front Travel
Rear Suspension
Rear Travel
Seat
Seat Height
Alt. Seat Height
Total Height1,015 mm (40.0 inches)
Total Length1,860 mm (73.2 inches)
Total Width655 mm (25.8 inches)
Ground Clearance
Wheelbase
Dry Weight61.0 kg (134.5 pounds)
Wet Weight70.0 kg (154.3 pounds)
Wheels & Brakes
Front Tire/Tyre
Rear Tire/Tyre
Front BrakesExpanding brake (drum brake)
Front Brake Diameter
Rear BrakesExpanding brake (drum brake)
Rear Brake Diameter
Wheels
Comments