The 1978 Suzuki JR50 is a miniature, off-road motorcycle designed for children, featuring a 49cc two-stroke engine and a single-speed automatic transmission with a centrifugal clutch. 
Engine & Performance Specifications
Engine Type: 49cc, air-cooled, two-stroke, single-cylinder.
Lubrication: Oil injection system with a separate oil tank.
Carburetion: Mikuni VM12 carburetor.
Max Power: Approximately 3.26 horsepower at 5,000 rpm.
Starter: Kick start.
Ignition: Magneto.
Speed Control: Includes a removable exhaust restrictor plate to limit top speed to around 13 mph for beginners, or up to 30 mph when removed. 
Chassis & Dimensions
Transmission: Single-speed automatic with a centrifugal clutch.
Frame: Steel, tubular.
Weight (Dry): 84 lbs (38 kg).
Seat Height: 18.2 to 19 inches (approx. 480 mm).
Fuel Capacity: Approximately 0.5 gallons (2 liters).
Tires: 2.50 x 10" front and rear knobby tires. 
Suspension & Brakes
Front Suspension: Adjustable telescopic fork.
Rear Suspension: Two adjustable shock absorbers.
Brakes: 90 mm drum brakes on both the front and rear wheels.