Well, I just reacquainted myself with my Z50A, K1. With a charged battery connected in the circuit and the ignition switch in the second position, the headlight and high beam indicator will illuminate with the engine not operating. Without a battery in the circuit, the engine must be operating for all lights to operate. Also, strangely enough, both brake light switches will illuminate the brake light (battery connected in circuit) with the ignition key in your pocket.
Here's the wiring diagram for the Z50A, K1.