Why does fuel shoot out of the top of a rochester 2 barrel carb?
Possibly the float is stuck or the needle valve is stuck or has dirt in it. Clamp off the fuel line going to the carb so no new fuel can get in. Start the vehicle & run it till it runs out of fuel. By doing this if you're lucky whatever is stuck in the valve may sink to the bottom of the bowl. Unclamp the fuel line after the engine runs out of fuel and restart the engine. Hopefully it will now be o/k and save you having to disassemble the carb. If it still does it, it's time to disassemble and while you're at it you might as well put in a kit.
What is the gas mileage on a 350 motor with a four barrel carb compared to a 350 with a two barrel carb?
If equipped with the stock Rochester Quadrajet carb, there is a small fuel filter inside the carb in front right where the fuel line goes in. That may have been removed, however, and replaced with an aftermarket in-line fuel filter that could be cloated pretty much anywhere, but usually somewhat before the carb in the fuel stream.
The fuel filter is located in the carb. Follow the fuel line from the fuel pump into the base of the carb. There is a boxy type part, and that contains the fuel filter. You'll need two wrenches, and carefully remove the fuel line. The fuel filter is spring loaded, so be careful it doesnt shoot out! -OSS
Provided it is all factory.....it will be in the Rochester carb. Where the fuel line mounts to it. The fuel line screws in to the fuel filter housing. You'll need to remove the line, then remove the housing. However, most people end up putting an inline filter on.....which could be located anywhere between the fuel tank and the carb.
Most of the Rochester carbs were factory rated at 750 cfm; but this was a airflow rating only; unlike performance carbs that are flowed with a air and fuel mix. When the factory Rochester carb is wet flowed like a Holley carb, the flow rating of the carb is adjusted to around 470-500cfm. I hope this helps you. Mark