Yamaha atv engine help?

Yamaha Badger YMF80-4 stroke, with auto clutch 4 speed. so since the battery went bad, it has no kick start so we would have it in neutral and push it, then shift into 1st and it would start. so the last time we did tryd that the atv stoped and the tires dont spin but if you put in in 4th grear you can roll the atv super slow, so what happend to the engine? i would like to take it apart and try to fix it, but it would help to know where the problem is before i start taking the engine apart.|||Can't begin to imagine how you can push-start something with an automatic clutch unless there's something wrong with the clutch i.e. it's not disengaging properly, so I would say start by pulling the clutch apart and servicing/repairing it. It is always harder to push a vehicle in gear in first than in top, so the symptoms you describe lead me to that conclusion.|||could be timing chain... broken or jumped a tooth???