motor bicycle electrical

I recently went on a 2-3 mile trip on my bike, just riding around with a friend. I dropped my allen key set, went to go pick it up, and and soon as I picked it up my bike shut off. Since then, I haven't been able to get it to start. I drained all the fuel, put new gas in, replaced the...

Can anyone tell me what to do if my engine came without a white wire for a light?? can i still hook something up and how?? would i just bridge into the blue wire or is there somewhere else i should be wiring the light to?? thansks again sooo much