A primer switch would eliminate any cold starting probs you may encounter.
Simply turn the ignition on, hold the button for a few seconds to fill the vapour hose with gas, release button & kick it in the guts. No Problemo!
I have used a primer switch on a car with approx 4ft of vapour hose. This thing would have been extremely hard to start had it not had the primer installed, but once primed & the hose filled the gas nowhere to go except into the engine...