The Fuel return pipe on my '78 tank seems to have some obstruction. Should it be completely clear like the other tubes? If so, any ideas how to clear it?

 

Return line whould be free flowing towards the tank but not back to the carb. Start with the restrictor in the rubber line between the carb and the hardline line at the firewall. It's a oneway valve going to the tank. If that's good, try blowing the rest of the line out and check fo any pinching in the rubber lines in the engine bay and near the tank. How do you know know it's obstructed?