Headlights for kart

[Jokersace69]

This one is a little different from what i have searched so bare with me.

I have a Subaru ex 21 engine and finally have it running perfectly.
When i first bought this kart it came with dual headlights, over the years the bulbs burnt out and never got around to replacing them so i took the lights off.

Since I'm now building the kart back to original amenities i want to have lights back on the kart ( lost the originals in a move ) I'm not sure of the bulb voltage but i have the manual and i will look it up when the time comes.

The kart does not need a battery, alternator, or anything else. I remember the lights just hooked right on up to the engine. Below is a picture of my wiring that is on my engine.

How would i wire this?
Any help is greatly appreciated!