Do 250's use an AC based CDI?
 

I read elsewhere that 250's use a DC based CDI but the one wierd thing about this Coolster that I just got makes me think it is AC based! The ignition switch has three leads. 1 is power coming in, 2 is standard DC power going on (i.e. ON) and the third is for kicking the starter. When you shut this machine off....it stays running until you hit the kill button!

The only explanation I can come up with would be that this is actually AC based CDI. The thought process is that when I kill the power, thus killing the DC based power supply, it stays running because AC power is being provided by the stator.

Anyone have any thoughts on that?

it could be ac, instead of the kill wire going to the key switch they used the kill button. that wire should go to the cdi. we have had a few coolsters in the shop that were that way

The stator is actually sends a DC current. And CDI has nothing to do with your key switch.
Your battery sends a DC current that is what is used for starting the engine. The stator produces power to run everything else including the CDI, lights and charging the battery. I don't get what your saying when you say shut the machine off but the engine still runs, but it has nothing to do with the CDI. Also when you hit the kill button it just grounds the ignition so instead of the power going to the plug it gets grounded to the frame or the engine or wherever it is. So if this doesn't help please tell me why and I will try to explain it better.

The stator sends A/C and gets converted to DC via the rectifier. I know some of these machines run the CDI off of A/C, and some off of DC (such as the Helix and Carbide).

In the case of this coolster, BigE is right. It simply grounded it out to kill it.

Well yea your right. I'm new to this whole buggy thing. But the two strokes that I work on usually have a DC current. I'm mean I draw a blank when you say Helix or Carbide or Coolster. So ill work on getting that knowledge up.