with the key on the headlights or taillights wont come on. if i switch the key off all lights work and come on. i have replaced the ignition and put a new battery in it. other than that i have not done anything else electrical to it.

 

Seems like you have fitted a wrong ignition switch. This switch cuts power to everything connected to the battery except the voltage regulator on most bikes. However the 420 electrics are insanely complex, with two relays in the battery box as well as the solenoid, and an extra tiny voltage regulator, as well as the EFI system. It is just possible one of those relays is feeding power back through the system with ignition off. If you are sure the ignition switch is OK, try swapping the relays round, the fault will change to something else if one of them is bad.