Engine possesed by demon

[warriorpoet]

Hey guys,
so i went to start my bike today and none of the electronics turned on. I figured the battery was dead so i push started the bike to recharge the battery.(super fun to do since Florida is still 90 degrees in january....not) I got her fired up but the throttle was very unresponsive. Any time i would give her gas the engine would sputter with the occasional backfire, but speed would not increase. Anytime i completely let go of the throttle she would settle at about 10 mph but would not drop any slower. By the time i got back to the driveway the engine was smoking white where the exhaust meets the engine. I shut her down and the battery had not charged at all(i rode her in second gear for about 10 minutes.) Battery is 8 months old and she was working fine last week. One last detail is when I would give her any gas it sounded like something was banging around in the engine, very not good. Anyone have any idea what this could be? thanks