The sound is like a “hard start” like it’s really trying to start.…no backfire, or popping really. Yes it fired once! There is a little smoke. We used fresh ethanol free gas from a clean jug, (not from the truck tank) we blew out the metal fuel line and tried to see if the fuel pump was working but couldn’t really tell since it didn’t start, so we abandoned that and bought a flexible fuel line and attached funnel to end and other end to carburetor.
