@Jackk525 welcome here!
As you might already know our 500i's are prone to start probs.
I would start with basics.
-kill switch ON/OFF?
-sidestand switch in working order?
-brakelight on when lever pulled?
-all connectors really tight?
-groundcable from battery minus to motor in order?
-all pins in your ECU connector straight?
-this two thin cables to your coil conductive and tight?
-take jump cables and connect your scoots batt to a cars battery or any other known healthy big battery
(car idles and headlights on)
-try to start, YES/NO
-multimeter: unplug two cables TO coil, start, DO we have voltage UNTIL here?
-if yes, your scoots batt or coil is shot
-if no, take a NEW sparkplug, NEW sparkplug cap
-long sparkplug cap really tight on plug?
TEST: sparkplug cap OFF, new plug into cap, starting, is there a spark? (plug tread on ground)
-yes/no
-if no, unplug/plug the rectifiers TWO connectors
-jumpstart battery, start..
-yes/no
Q? Came the new coil with a cable and cap or just the coil?
Qs: pls come back to ask