ClassicCar

As long as the float is closer to the road, or touches the fuel sooner.

The problem arises because the float level setting is done by a fixed measurement between the seam of the float, and the raised section of the float bowl, and measuring the distance thereof. This takes no account of the different specific gravity of modern fuel compared to the fuel that was used in 1935. The old gasoline was "denser", therefore it raised the float sooner, and cut the supply off, which allowed a specific amount to be drawn trhough the jets. With modern fuel, the lighter fuel doesn't raise the float as quickly, hence the actual level in the bowl is higher, and because the fuel is "thinner" it allows much more to be drawn through the jets, and flooding and rich running results. This applies to modern unleaded gasoline. However, I don't know what is going to be the result now that bio-fuels are coming in. I understand that these are even more prone to vapor-locking, but I don't know what the specific gravity will be.

Geoff.