New stator cover bike wont start

Useing a multimeter set to d.c check your charge at the battery whith out the motor running it should read above 12 volts determine the voltage stored in the battery with the meter stil conected hit the start button if the meter shows a dramatic drop in voltage its almost certain that the battery is shot howevwer if the voltage does not drop & it wont start bump start it conect the meter still set on dc increase the revs asyou do this the voltage should climb to 13.50 if it does & maintains 13.50 to 13.65 the chargeing system can be declared ok & you only need replace the battery however if it goes above 14 volts the voltage regulator is faulty & cooking the battery so you will need to replace both