Fuel feed air lock

rusty_apache

My 29 Essex fuel feed canister gravity flows perfectly but if I allow the fuel feed to empty, entirely down to the glass sediment bowl it develops an air bubble in the small chamber just above it, no amount of fuel in the canister will push out the air bubble and fuel does not gravity flow into the carburetor.

When I shake the car from side to side it is very clear that the bubble moves but will not burp up into the next chamber. I have double checked the spring loaded conical shutoff stopper and it is not preventing the fuel from flowing in or air from escaping upwards.

What am I missing here?

Geoff

Is the vent hole in the top of the tank clear?

rusty_apache

Yes, thanks for the suggestion, actually that is a frequent issue in south Texas! Tiny mud dauber wasps plug up vents often so I wrap them in window screen material.

I may have also had the coil spring in the wrong location. My reference materials are difficult to see well enough to know. This photograph is where it is currently located.

I also rerouted the fuel line to allow for a little slope up and away from the carburetor. I started the engine and kept adding fuel to the carburetor bowl manually and as the carburetor float dropped, I noticed some bubbles emerging from the needle valve. Shortly

the dreaded bubble atop the sediment bowl was gone.

Another thing was certainly unhelpful, the fuel tank was empty.

Geoff

The coil spring should be under the valve wires.

rusty_apache

Thanks for the information, I’ll correct that!