I have a husqvarna 55 that won't run unless I hold the choke halfway out. I have gone through all of the normal "starving for gas" issues and it stays the same. I have rebuilt the carb, changed the fuel filter and left the filter off. I have cleaned all of the ports and holes in the carb when I rebuilt, even took out the metal plug in the carb and cleaned out the holes their. Checked the gas line and is not plugged (mouthfull of gas with no problem). Still runs exactly the same. Removed the fuel vent and ran without it in place, still won't run unless I hold the choke in a certain spot (about halfway).