These are the known mechanical and performance specifications for your 1947–1954 Royal Enfield Royal Enfield Model J2 500.
Basic Specs

Engine
Displacement500cc
Typeohv single twin port
Details500cc ohv single twin port
Max RPM
Compression
Bore/Stroke
Valves/Cylinder
Fueling
Ignition
Exhaust
Lubrication
Cooling
Chassis
Frame Type
Rake
Trail
Front Suspension
Front Travel
Rear Suspension
Rear Travel
Seat
Seat Height
Alt. Seat Height
Total Height
Total Length
Total Width
Ground Clearance
Wheelbase
Dry Weight
Wet Weight
Wheels & Brakes
Front Tire/Tyre
Rear Tire/Tyre
Front Brakes
Front Brake Diameter
Rear Brakes
Rear Brake Diameter
Wheels
Comments
Post-war Production: A rigid framed telescopic fork model, it offered a flashy twinport exhaust system - twin exhaust pipes one each side of the bike.