Having issues with the starter on my wifes Z400. Usually able to start it right up but now seems about 80% of the time it won't crank over without having the charger hooked up. I just replaced the battery and it didn't help. Put volt meter on it and its showing 12.6 or so with engine off and almost 14 while running. But when I hit the starter button it will barely crank over, toss the charger on there and cranks over fast and fires right up. What could this be? Went to check to make sure wires to starter were tight and the power wire on the starter was very hot and burnt my finger.