My st2 lives in interior Alaska in a little mine shack.  Instead of keeping the shack warm, I have been dropping the engine to idle overnight with only a couple led lights and a 1500w heater on line.  Recently I was gone for three days and the engine eventually ran out of fuel.  When I returned and got the unit warmed up enough to start it back up it would only run at about half the normal rpm with a tremendous amount of smoke [the smoking never happened when it ran at idle].  I bled the injectors but there was no change in rpm.  Any ideas of what I might try?