First let me welcome you to the forum. We're here to help and maybe this link > http://motorbicycling.com/showthread.php?t=35090
will get you going.
We're assuming by "coil" you mean the CDI, or the little black box. It is actually the heart of the ignition system and they typically don't fail. Check your wiring connections carefully and try not connecting the kill switch. Also I suggest you replace the kit supplied spark plug and plug boot with automotive quality items. The plastic boot might be your problem. They are notorious for having bad electrical connections.
Let us know after you have read through the link if you found the problem.