These are the known mechanical and performance specifications for your 2017 Rieju RS3 NKD 50.
Basic Specs

Engine
Displacement50.00 ccm (3.05 cubic inches)
TypeMinarelli NG 50 engine
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
Exhaust
LubricationWet sump
CoolingLiquid
Fuel Economy & Polution
Fuel Consumption
Fuel Capacity12.00 litres (3.17 gallons)
Emissions
Chassis
Frame TypeTriangular double cradle double steel tube
Rake
Trail
Front SuspensionInverted fork of Ø41mm.
Front Travel
Rear SuspensionMono-shock shock absorber adjustable
Rear Travel
Seat
Seat Height845 mm (33.3 inches) If adjustable, lowest setting.
Alt. Seat Height
Total Height1,090 mm (42.9 inches)
Total Length2,020 mm (79.5 inches)
Total Width770 mm (30.3 inches)
Ground Clearance
Wheelbase1,375 mm (54.1 inches)
Dry Weight119.0 kg (262.4 pounds)
Wet Weight
Wheels & Brakes
Front Tire/Tyre100/80-17
Rear Tire/Tyre130/80-17
Front BrakesSingle disc. Wave disc
Front Brake Diameter300 mm (11.8 inches)
Rear BrakesSingle disc. Wave disc
Rear Brake Diameter220 mm (8.7 inches)
Wheels
Comments
Spanish brand.