With a battery ignition, your spark is only as good as your battery. If your relying on the stater to keep it running then you dont have that great of spark. In short, your battery is the sparks performance. I doubt anything is wrong with the stator do to those are protected by diodes. Your ampmeter is pegged becouse it's trying to keep up with everything electrical that by rights the battery should be doing. Get you a new bettery and i vouch to say, end of trouble.