The Coleman "Xponent" series used a liquid fuel feed and was excellent, so good that they were discontinued - why - so Coleman could market their junk without having to compete with their own excellent product? madCalling these "exponent" is almost fraudulent mad madand is certainly meant to confuse the public. madThe F1 is just another on top mini burner that cools the fuel bottle as gas inside it gasifies and passes through the nozzle. The output will go down as with all top type burners because as a molecule of fuel does evaporate from the liquid it has to travel further , while bouncing off the inner walls, before it finds the outlet.
Jim ok soap box off again. mad
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These are my own opinions based on wisdom earned through many wrong decisions. Your mileage may vary.