Craftsman tractor runs on either

So I have a craftsman 917 254750 12.5 hp lawn tractor. I use it to cut my back field. It has been good for years , I don't really take great care if it.

Now it only starts with either then dies. Or I can pour gas right down the intake and it will run too. What gives??

Also I start it by hitting the starter directly with a jumper cable from the truck . Burn something out??