What is the purpose of the float in a carb? What is the effect of float height? What is the effect of float drop? Is it kinda like a float in a toilet?

:hail:IROC-Z

 

Rocky,

Good analogy. It's almost exactly like the float in a toilet. The toilet float regulates the level of water in the toilet tank, just like the float in a carburetor. The point where it closes the inlet valve completely is critical to prevent overflow - just like in a carburetor bowl.

Float drop is the amount that the float will lower before stopping - not quite as critial as float level but indicative of how much the inlet valve can open.

The big difference between the toilet tank float and the carburetor float is that a toilet tank only empties when you flip the handle, then all at once. A carburetor bowl is being constantly emptied as the engine operates, so the float is constantly operating the inlet valve to maintain fuel level.

As for the effect of float level, or "height", the carburetor withdraws fuel using the air moving through the venturis in a carburetor, creating a slight vacuum, and "sucking" the fuel up and over a metering well that is more like a spillway than anything else. If the level of the fuel is maintained above the "spillway", fuel will constantly overflow and cerate an overly rich condition. A fuel level that is maintained too low will cause less fuel to be "sucked" up over this spillway, creating a lean condition. Correct fuel level is crucial for correct mixture control. Therefore, adjusting the float is critical

 

The float controls the level of fuel in the bowl, pretty much like the float in a toilet. If the float level is set too high, fuel can slosh out and cause flooding during maneuvering. Too low and it could get drained too quickly and go lean on acceleration.

 

Thanks guys.:rockon:

:hail:IROC-Z