These are the known mechanical and performance specifications for your 2013 Rieju Marathon 125 AC.
Basic Specs

Engine
Displacement125.00 ccm (7.63 cubic inches)
Type
DetailsSingle cylinder, four-stroke
Max RPM
Compression
Bore/Stroke54.0 x 54.0 mm (2.1 x 2.1 inches)
Valves/Cylinder4
FuelingCarburettor. VM26SS
Ignition
ExhaustRacing Muffle
Lubrication
CoolingAir
Fuel Economy & Polution
Fuel Consumption
Fuel Capacity6.30 litres (1.66 gallons)
Emissions
Chassis
Frame TypeSteel dual beam perimeter
Rake
Trail
Front SuspensionFork of Ø36mm.
Front Travel
Rear SuspensionMono-shock shock absorber
Rear Travel
Seat
Seat Height850 mm (33.5 inches) If adjustable, lowest setting.
Alt. Seat Height
Total Height1,165 mm (45.9 inches)
Total Length2,150 mm (84.6 inches)
Total Width800 mm (31.5 inches)
Ground Clearance
Wheelbase1,405 mm (55.3 inches)
Dry Weight105.0 kg (231.5 pounds)
Wet Weight
Wheels & Brakes
Front Tire/Tyre90/90-21
Rear Tire/Tyre120/80-18
Front BrakesSingle disc. Double piston caliper.
Front Brake Diameter260 mm (10.2 inches)
Rear BrakesSingle disc
Rear Brake Diameter200 mm (7.9 inches)
WheelsAlloy Rims
Comments
Spanish brand