RE: What causes a P120 to Flame Out
White smoke trail is a pretty good indication of a fuel system problem. Check tanks venting, check for air getting into fuel lines, check fuel filter for starters.
If this problem has only recently begun to show up check your pump, run your pump in manual at a fairly high pump voltage draining into a second container and check that the pump runs continuously with no skips or hiccups, when the brushes and armature wears out, this is the result.