[COUPERS-TECH] fuel transfer problem

[Bill Herridge]

----[Please read http://ercoupers.com/disclaimer.htm before following any advice in this forum.]---- Fellow 'Coupers--   My 1946 415C (N99790) has a real problem with the fuel system.  Here's what happens.  I fill up the header tank and both wing tanks and head out.  The left tank goes dry very quickly, and fuel can be seen misting out of the right side filler cap.  The header tank then starts to deplete, and the right tank stays full.  After an hour or so, the float on the left tank is bottomed out and the header tank float gets very, very low, but the right tank stays full.   After landing, you can hear gurgeling and the right tank slowly drains into the left tank, takes about 15 mintes for them to equalize.  My mechanic has removed and blown out all the associated fuel lines.  He has found that the fuel shut-off valve has metric retaining nuts, and the exit side of the valve is much smaller in diameter than the entrance side.  He thinks somewhere down the line someone put in a valve that was not intended for 'Coupe use.    He has removed and inspected all three tanks, and found them clean and free of crud.  All straining meshes in the system are clean and clear.  We know the fuel pump is working because of the way the left tank depletes and the header tank stays full until the left tank is empty.   Does anybody have any thoughts about that valve with the two different sized ports?  This is not a problem if flying locally and for no more than an hour or so, but any longer than that and I start sweating the fuel and usually land prematurely to top off the left tank and header before continuing.  Being a former Comanche driver, I'm still learning the ins and outs of the 'Coupe.  Is this normal function for the fuel system?  Any help would be appreciated.   Bill Herridge Gatesville, Texas ========================== To leave this forum go to: http://ercoupers.com/lists.htm Search the archives on http://escribe.com/aviation/coupers-tech/