Small Engines (Lawn Mowers, etc.): briggs motor, hp briggs, coil wire

Question
ok i got a 19.5 hp briggs engine off a craftsman lawnmower i am using it for a go kart. my problem is that i have 3 wires coming out from under the flywheel and fan, etc. one being blue which is positive and the other two are orange and black both being neg. well according to my multimeter but shouldn't there be 2 positive and one neg. help me please i am almost positive that the blue is my ignition coil wire but i am lost after that. help  

Answer
Hiya John-
Your mower Does have a rectifier- so BE CAREFUL!  My 19 hp has an orange, red and black wire from the alternator.  The orange is a straight 14vac(non-rectified) this supplys the headlights.  The red is 14vdc (rectified) that is charging system output, goes to ignition switch + ammeter.  Black is the ground for the alternator.  So- in my case, I wouldn't want to ground the RED wire while its running.  Ignition wires don't come out from under here- ignition comes from the switch, goes to the ignition unit, then to the plugs.

If you have a DVM, you can verify the above for your mower.  Red to black should read hi/low resistance (swapping the leads) because of the diode in the circuit.  Hope this helps