I have a 500 classic and just rebuilt the engine. I had to buy a new cdi for it and it did start for a second until the pull cord broke. We fixed that, but now my cdi doesn't work again. Is there a way to test it or is it just a dud. What could cause this to die like that grounding? I have a manual but it doesn't seem to help I can get readings from the stator but not the cdi.