Vapor lock or something else?

[Stinnett21]

I probably dealt with this for 1/3 of a season. It would only occur on the hottest of days. Come fall when it cooled down the problem went away. Once I suspected it was due to vapor lock I would loosen the fuel filter and let it breath a bit, retighten and it would restart.

 

[jimmbo]

Back in the Days of Carburetors, and Fuel Pumps on the Engines the pulled Fuel from the Tanks, Vapour Lock was common on hot Days(Gets a lot Hotter under the Hood of a Car, compared to the Bilge/Engine Compartment of a boat) I would carry a bottle of Water that I would Pour on the Fuel Pump, and the Line feeding it. Rarely did the Line from the Pump to the Carb need cooling as it was under Pressure, but if Hot enough the Fuel in it would Flash, and the rising Pressure would force the Inlet Valve in the Carb open, flooding the Carb. That is not Vapour Lock, that is called Percolation, Cooling that line would reduce that.