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

Engine
Displacement125.00 ccm (7.63 cubic inches)
TypeYamha engine
DetailsSingle cylinder, four-stroke
Max RPM
Compression
Bore/Stroke52.0 x 58.6 mm (2.0 x 2.3 inches)
Valves/Cylinder4
FuelingCarburettor. Keihin CVEK 30
Ignition
ExhaustInox
Lubrication
CoolingLiquid
Fuel Economy & Polution
Fuel Consumption
Fuel Capacity6.30 litres (1.66 gallons)
Emissions
Chassis
Frame TypeDouble cradle. Highly resistant steel perimeter
Rake
Trail
Front SuspensionMarzocchi fork of Ø40mm.
Front Travel
Rear SuspensionMono-shock shock absorber PRS system
Rear Travel
Seat
Seat Height870 mm (34.3 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 Weight115.0 kg (253.5 pounds)
Wet Weight
Wheels & Brakes
Front Tire/Tyre90/90-21
Rear Tire/Tyre120/80-18
Front BrakesSingle disc. Galfer Wave. AJP double piston caliper.
Front Brake Diameter300 mm (11.8 inches)
Rear BrakesSingle disc. Galfer Wave
Rear Brake Diameter200 mm (7.9 inches)
WheelsAlloy Rims
Comments
Spanish made bike