New member wit problem

Hi everyone
My bike is a TRX500 fped 2013
It stopped suddenly last week and would not start again as there was no spark I tested regulator/rectifier and found a rubbed wire on a little box beside the main rectifier (not sure what that is) so solid in a new splice of wire and resealed I now have spark and checked injector and it's also firing fuel but still no start
Not sure what could be wrong so any ideas would be welcome