I don't have a wiring diagram but if the cub uses a battery, make sure it is capable of accepting a charge and the connections are good. Otherwise, the alternator output voltage will increase to the point of blowing bulbs.
You should also check the rectifier, any wiring diagram will work for that.
If the bike is designed to run without a battery, make sure you have all the bulbs working and they are the correct wattage. When one bulb burns out, replace it immediately as the voltage increases to the rest.