I've got a 72 bonneville, went to start one day and it fired but was idling real low as soon as i gave it throttle it would die. Carbs clean, battery was low and not holding charge so I replaced it, ran about 4 miles and bike stalled and wouldn't start again and no headlight. Second battery cooked. Bought another battery and put it in this time checking with voltmeter, was all over the place, 14v to 16v + at idle. replaced sparx regulator this did nothing. Realized I had not used resisted plug caps when changed recently, put some on, now reading what it should high 13 to low 14v and not jumping all over. Thought it was fixed, rode about 5 miles bike stalled and will not restart. Noticed a crack in my coil? could this be a cause for batteries crapping out?