HELP WITH 05 660R Starting problem

I was riding when I heard chain slippage. I nursed it home and after downshifting in front of the house, the engine died. It would crank over but not start. While waiting for the part I changed the oil and then replaced the worn front sprocket and tried to fire it up. It cranks over but no spark. After reading every post here, I disconnected the wire on the rectifiyer and it started right up. When I reconnected the the rectifiyer it stalled. I have replaced the coil and plug with new ones and cleaned all the connections. Can anyone help? :3question: :3question: