Fuel Blowing Out Carb Vent Tubes Under Heavy Throttle: Expert Opinions Please

The thing is, you can adjust the float level to wherever you want. There are two many variations to say it has to be a certain way. Fuel makeup and therefore density, air cleaner restriction (on the vents), engine angle, fuel pump pressure and many other variables all affect the fuel level in the float bowl. If it doesn't normally flood out your needles and seats are obviously working, so there is another issue. I have always adjusted mine to the bottom of the sight glass or opening, so that you can just see it if you rock the vehicle. You can also fine tune mixture by adjusting the float level. You are way better off too low, than too high and coming out the vents.

Drop the float level and I would bet your issue goes away. And stay away from ethanol laced fuel..... use real gasoline if you can get it.