I have a 1967 Alon A-2 Aircoupe in which the previous owner removed the header tank and replaced the 7.5 gallon wing tanks with the 15 gallon units. I have flown this plane for the past 1.5 years with no problems until lately. I have noticed that during flight, the right wing tank does not empty (i.e. after a flight, the left wing tank fuel level is down while the right wing tank fuel level remains at the same level as when the flight was initiated).
The fuel cap vents are patent (checked multiple times). I have had two AP mechanics inspect the fuel lines and fuel line/tank strainer - all clean. While the airplane is sitting on the ground, the fuel freely drains from the right wing tank. In fact, fuel can be placed only in the right tank and after sitting for a short period of time, the fuel transfers to the left tank until the two tank levels are even. This was not a problem until just recently. Has anyone had similar experiences with the 15 gallon wing tanks? Any suggestions? Thanks, David
