Honda introduced the Super Cub, also known as the "Cub," in 1958. Technically, Honda's Cub was a 1/2-horsepower two-stroke engine designed in 1952 to attach to a bicycle -- a simple engine with few electronic components or wires. Super Cubs also went by names C90 or C50, indicating the engine size; Honda discontinued them in the 1980s. Electrical problems with these classic, step-through scooters often have the same electrical issues that also affect other older motorcycles.
Check to see if the bike's battery is charged. Motorcycle batteries don't last as long as car batteries. If the Cub's battery won't maintain a charge, either the alternator is malfunctioning or the battery needs to be replaced.
Locate the fuse(s) on the Cub. Electrical issues can be traced back to blown fuses, which should be replaced.
The Super Cub's electrical/ignition system is typical of motorcycles of that era, consisting of a battery, starter motor, rectifier/regulator, points/condensor, ignition coil, ignition (or spark plug) wires, and spark plugs. Each of these components is prone to failure. Replace a component if it is worn, damaged or non-functioning.
Wiring harness and connections
Check the bike's wiring harness. Unlike a vehicle, the wiring on the Cub is exposed to the elements -- despite some protection provided by cowlings and bodywork -- and thus more often exposed to physical damage. One common problem is simply a nick in the wire's coating. Hf the exposed wire gets close enough to, or comes into contact with, other wiring or metal, problems will occur. The wiring insulation can also become brittle and break. Oxidation of the connections, which interferes with a positive electrical connection, is another common problem.