[H. L. Chauvin]

Hi Rene,

Also, according to some Model A owners who have monitored carburetor fuel levels when a Model A engine is "not" running vs. when engine "is" running, the fuel level in the carburetor bowl was observed to drop an additional 1/8" when the engine is running at a slow idle.

As one can imagine, to provide a constant flow of fuel when the engine is running, the float has to drop downwards, (in order to supply a constant flow of fuel), to open the float valve above.

With an engine running, with a slightly lower fuel level plus the float moving further downwards, the volume of the space between the bottom of the round float and the bottom of the round carburetor bowl is lessened.

When Mr. Rex Rheis suggest lowering the recommended bowl fuel level, this space between the bottom of the bowl and the bottom of the carburetor is lessened even further which may help to impede the forward "sloshing" of fuel and fuel starvation ....... then increasing engine RPM's may make the bowl drop further downwards which may decrease forward "sloshing" of fuel.

Then with the intake valves drawing fuel from the orifice in the bottom rear of the carburetor bowl, and the fuel "sloshing" forward, the bottom rear of the carburetor is starving for fuel ...... but the intake valves are still getting the same amount of air which makes the engine operate with a leaner fuel mixture.

Also as mentioned further above, leaking carburetor butterflies, and leaking intake manifolds can increase air flow which makes the fuel mixture even leaner during abrupt stops.

Never tried it, but maybe a hollowed out concave rear carburetor bowl fuel reservoir accompanied with a partial screen dam may help eliminate this problem ...... still LOL.