The ercoupe had a most interesting fuel system. It had two wing tanks
(9 gal each and cross connected) plus a header tank of 5 gal (later 6
gal) The engine driven pump continually pumped fuel from the wing
tanks to the header tank. An overflow system allowed the excess to
drain back to the mains. The carburetor was gravity fed from the
header. A float wire showed how much fuel was in the header. When
the wing tanks ran dry the floating indicator would slowly start to
go down. When the header tank was full you had about an hour of
flight left. Many owners cut the float wire length to indicate about
15 minutes of fuel used. The advantage was when the wire was suddenly
even with the cap you knew that you had about 45 minutes left and it
was more attention grabbing than wondering if the float wire had gone
down a bit or not. This system did not require a back up pump as if
the engine driven pump should fail you still had about an hour
remaining. The disadvantage was the same as with all header tanks/
gravity feed systems, low fuel pressure and under certain conditions
(especially with auto fuel) vapor lock is more likely to occur. I
know of one ercoupe that this happened to here in AZ. The pilot
waited till late afternoon before trying again. The cooler weather
corrected the problem, but he modified the fuel line to the carb by
mounting it farther away from the heat from the exhaust and installed
a better baffle. This seemed to cure his problem,
