Back in the 60s, while working for a Vickers station, I used to see a lot of people with wooden clothes pins on the fuel line. They said it fixed their vapor lock, but I don't understand how.
They were probably using the clothes pin in place of a metal bracket or clamp that was transferring heat directly to the fuel line and causing vapor lock. A wooden clothes pin would act as an "insulator" and not allow the heat to travel thru it to the fuel line.
