i replaced the motor in june ran fine until last month. i was having a problem a least month where it would crank fine just would take a couple cranks to start. put a new battery in new alternator in not that long ago. it was doing fine but just earlier i was driving it gave it some gas and it wanted to stall but continued going didn’t think about it. got to a stop sign went to go and it stalled tried starting it up and it didn’t want to. pushed it to the side of the road went to start it up and a puff of smoke shot out and all you could smell is gas.

any suggestions on what it could be?

one of my buddys said head gasket but i’m not sure if that’s it