i turn the switch with the key and no lights ,no starter but i can start with the kickstart??????? where is my problem ???

 

Probably the main fuses in the battery box, or the wires to them. Water and dirt tends to work its way into the box and corrodes the wires, so check you have power to the fuses. The 300 also has a habit of breaking the wires to/from the ignition switch around the "back box" on the steering column, but I think this would cut ignition, so bike wouldn't start by kick.

 

There should be a red connector in the battery box try cleaning it. My 89' had this happen the other day and we just started wiggling stuff in the battery box until we found the issue connector.We took some sandpaper and clean the metal part in the connector and now it works great.