Gas Float Levels

I know, that I'll get a sqazillion responses to this about reading previous messages and links and all that and Yes, I know there is a measurement of gas level in the float bowls with a plus and minus tolerance.

My question is ........ I'm assuming that the gas level is to ensure that both the main and idle jets are submerged in gas whilst running to ensure that the correct amount of "head" of gas is available for each circuit as the air going through the carb draws the idle or main circuit as required.

I'm after a simple Yes or No in ways of answers.

I'm sure the answer is Yes, but I just want to make sure

P.S. Won't be riding the Seca today as it's still in pieces, but the ZRX11 is ready to roll and I'm going riding ..............

 

Yes. Too low of a fuel level will alllow the bowl to "run dry" when fuel demand is at its peak. Too high and excess fuel will run into the carb throat without being atomized.

 

While not taking specifically about fuel levels, I think this vid from Max shows the venturi effect pretty well, and that's how these carbs work.

https://www.youtube.com/watch?v=y836ZPjvoMI

 

The answer is indeed YES, but the degree of such submersion has to be quite precise, hence the "+/-" specs being within a couple of millimeters.

 

Thanks Guys. Really appreciate that comments and help.

Cheers. Simon

 

It's not just an issue of the bowl running dry, etc. it has to do with the fuel mixtures, too.

In physical terms, the amount of vacuum pull (created by the venturi effect in the carb throats) is a somewhat fixed amount, for a particular motor, at a given point in time. This amount of pull is able to "work" on the fluid columns in the fuel passages of a specific amount (and at a specific rate).

If the fuel levels are too high, then this amount of "work" is going to draw proportionately more fuel into the fuel circuits, creating a fuel richness. Conversely, too low a fuel level will not allow as much fuel to be drawn into the engine, creating a lean condition.

Imagine sucking on a straw immersed into a drinking cup. You only have "so much" breath to use to apply the suction to a fixed size straw. If the fluid in the cup is "full", you can gulp a lot of fluid before you run out of breath. If the fluid in the cup is, say, 5 yard down in the cup (this is a really deep cup), then..........not so much fluid can be drawn up during a given breath. This is an extreme example, I know, but extreme examples are useful for understanding the basic concepts.

The fuel levels affect fuel mixtures. It's a coarse way of tuning and effect....it's nothing like manipulating the size of the fuel jet openings or the pilot mixture screw settings, but yes, it is real.