Fuselage Header Tank Overflow

Brady,

The floor wing tank shutoff valve was in the open position to allow wing fuel to transfer.  There was no more than about a quart of fuel in each of the wing tanks, essentially dry.

Tim

On a side note, when I topped off my wing tanks for my first cross country in my Ercoupe, I had the same issue on startup. My coupe had a freshly installed, new engine-driven fuel pump when I purchased it. The volume of fuel was only 3-4 ounces that exited around the fuel cap but when it started blowing on my windscreen, I definitely took notice. It didn't continue and it reminded me of other airplane fuel vents that drip fuel after fill up when the cool fuel expands in the warm wing tanks. I figured to never top off the tanks to 100% again and leave some room for expansion. In your case, that's interesting that it did the same thing without the wing tanks. Was your floor, fuel valve open or closed?

I recently purchased a 1946 415-C, SN 670,.  Following a thorough annual I took it out for a test flight.  All systems operated normally until I spent about 30 seconds at higher RPMs, north of 2000 RPM, and then fuel started venting out of the fuselage tank gas cap in large quantities and covering the windshield.  Naturally I shut it down.  I had a full fuselage tank and empty wing tanks since I only planned to fly less than an hour.  My current speculation is that the vent line that is supposed to return fuel from the fuselage tank back to the right wing tank to relieve pressure on the fuselage may be clogged.  The airplane has not flown in several years.  Do you have opinions on what might be causing the problem and/or potential solutions?

Thanks,

Tim