Header fuel tank

Just backing up what Kevin said. It's SOP to shut off the header fuel valve when you shut down the engine. I will quickly get a noticeable drip if I do not. Just the nature of the beast (Stromberg) I guess.

It's a Stromberg. Thanks for the info.

Do you have a Stromberg or marvel carb. If it is a Stromberg you will always need to turn the fuel off. Even after overhaul it drip.

I think I have found the problem. When the engine is not running the carburetor was found to have a constant drip. So now I shut the header tank valve off after each flight and it solved the problem. Looks like I may need to have the carburetor overhauled.

There is one version of the 6 gallon tank that has the input and outlet of the fuel pump on the bottom of the tank. The fuel lines go up into the tank creating stand pipes. It is possible for the stand pipes to corrode and cause the tank to drain into the wing tanks.

Kevin

There is only one outlet that might drain the tank, the supply line to the engine (the over flow return line outlet to the wing tanks is quite high). You might not notice a drippy leak if the gasoline is evaporating faster than the leak. Check all the fuel line to the engine connections. If there was a leak inside the cockpit, I would think you would smell gasoline when you open the canopy, so it is probably in the engine space.

Do you have a Stromberg carburetor? They also have been known to "weep", although I think that is mostly a problem in tail draggers, where the carb isn't level.