Went to a friends an hour away. Bike ran great. an hour our so later they wanted to see it. Started right up no problem. Fast forward 2 hours. I go to leave and battery is dead dead. Try to jump and voltage pulls down to 8-9v when key is turned on. Got the bike sta rted, it ran okay. Little misses here and there. I tried riding home, bike kept missing while riding. Finally stalled, totally dead battery and here I sit. What should I be looking for?