Yesterday I topped-off the coupe's fuel tank for a long cruise up the coast -- and it flooded the motor. How does that happen? Without the fuel-pump running, can the fuel advance all the way past the carbs????
It's just siphoning down hill. Don't tell me you never siphoned gas.... Any tiny speck of crud under the needle and seat of a carb and if it's a down draft carb it can and will empty the gas tank into the engine crank case if the gas tank is higher than the carburetor float bowl. That's why Model A's (and motorcycles) had a fuel shutoff valve. They had up draft carbs so the gas just went all over the ground. When "thrifty" Henry put the V8 with a downdraft carb in his 1932 cars he also went the the expense of adding a fuel pump to pump the gas up from the newly relocated gas tank that was now lower than the carburetor. Quit using the cowl tank!!! Immediately!!!!
Actually the tank is a custom fab'd fuel cell in the trunk that sits below the level of the carbs. That's why I'm confused.
It could be a loose piece of dirt that just happened to get under the needle and seat. I've had a loose piece of dirt cause an intermittent flooding condition. If it's stopped flooding, the dirt could have passed on through and be laying in the carb bowl.
The A in your avatar? Serious rake? Put the car on a level piece of road. Measure from the carb fuel bowl to the ground. Measure from the top surface of the gas in that tank when it's full-full. I think you're going to find the top of the gas level in the tank is higher than the top of the fuel level in the carb bowl. That's why it's siphoning. remedy #1 Don't fill it up that high ever again. #2 Lower the back end of the car so the top of the tank is never higher than the carbs. #3 Lower or shorten the tank, including the filler pipe so it 's lower than the carbs. Clean the crud out of that needle and seat too!
I had one of my 2G's on my 3x2 set up puke fuel constantly..while the engine ran and after i shut it off..It pooled fuel in my intake so bad that it was like trying to start a flooded engine..(well i guess it was) turned out that the carb ate a chunk of shit and it was hanging the float open..and some of that shit got into the pump too (accelerator) so it just sat there dousing my engine with fuel , if it needed it or not.. It was one of the secondary carbs also. I took the top off of it blew it out with air cleaned the bowl good, and so far so good. Mechanical pump..and low on fuel in the tank..
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