Your machinist needs to stick to a subject he understands. Over-carbureted engines don't get too much gas- - - - -they run terribly lean! Of course, as soon as the power valves open up due to very low manifold vacuum, they waste gas, but they generally don't get rich enough to wash down the cylinders. Too big, or too many carburetors make an engine try to run on mostly air, with very little gasoline. The lack of power makes the driver push the gas pedal open further, which drops manifold vacuum. If the carb has a vacuum-operated power valve, it goes full rich and stays there!
Jerry
