RoyJ wrote:
The float controls the level of gas in the float bowl, most carbs have a
small air inlet to keep it from air locking. On the primer bulb models,
this air inlet is hooked to the primer bulb. When you squeeze the bulb
the air pressure forces the gas down in the float bowl, and up into the
main needle, dumps raw gas into the carb throat. As soon as you remove
the pressure, the float needle opens a bit to replace the gas that was
pushed out. Radically simple.

And on some of them the bowl vent is a little hole in the center of the
bulb which gets "valved off" by your thumb covering it when you give the
primer bulb a push. Another very simple solution.

Jeff



OP snipped

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."