These are the known mechanical and performance specifications for your 2011 Rieju MRT Pro 50 SM.
Basic Specs

Engine
Displacement50.00 ccm (3.05 cubic inches)
Type
DetailsSingle cylinder, two-stroke
Max RPM
Compression
Bore/Stroke40.3 x 39.0 mm (1.6 x 1.5 inches)
Valves/Cylinder
FuelingCarburettor. Dell´Orto PHBN 16
Ignition
ExhaustMuffler with aluminium silencer
LubricationSeparate mixture
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 inverted fork of Ø40mm.
Front Travel
Rear SuspensionGas Mono-shock shock absorber and separate bottle PRS system
Rear Travel
Seat
Seat Height900 mm (35.4 inches) If adjustable, lowest setting.
Alt. Seat Height
Total Height1,150 mm (45.3 inches)
Total Length1,970 mm (77.6 inches)
Total Width750 mm (29.5 inches)
Ground Clearance
Wheelbase1,332 mm (52.4 inches)
Dry Weight96.5 kg (212.7 pounds)
Wet Weight
Wheels & Brakes
Front Tire/Tyre100/80-17
Rear Tire/Tyre130/70-17
Front BrakesSingle disc. Galfer wave disc of Ø300mm. with double piston caliper.
Front Brake Diameter
Rear BrakesSingle disc. Wave disc of Ø200mm.
Rear Brake Diameter
Wheels
Comments
Rieju is a Spanish brand.