I was given a DT 250 motor with little wiring letf on it. I now have the motor on a go-kart. It starts and runs fine until the power band should kick in. I have been told that the second coil is not working. I was also told there should be three coils but I can only see two. One for the spark and one for lighting I gess. The white wire is for lighting I belive because I get 12V from that. The yellow wire is not connected to anything. Where should it go????