Hear's a list of carbs that will work and these all have float bowls and have been used on briggs 5hps. briggs 5 horse updraft carb, tecumseh 5hp carb, mikuni vm22, and walbro pz22. you woold have to make an intake for the tecumseh carb but the briggs carb is made for the 5 horse and there is an intake made for the walbro pz22 sold by ec carbs that woold also work for the mikuni.
