im doing a d reg tzr 125 up that i got as a non runner. ive not been getting a spark but when i dissconnect the black and yellow wires from the cdi i do, i was wondering what the black and yellow wires do, and where they are ment to go. because im stumped

do you mean the black and yellow wire or the individual black wire and yellow wire?

right im looking in my haynes manual now and the black wire comes from the battery and goes to pretty much every part of the bike that has electrics. the yellow wire goes to the flywheel generator. and the brown and yellow wire, well it dosent seem to have any importance it just goes to a little square thing it isnt even in the key :S.

hope this helps.