Ed:
I fly an EC with the C-90. For what it is, it has pretty decent performance. The EC and FC are a bit heavier than the earlier models, due to the electrical system and the interior trim. The gross weight is higher, though, which does two things: the useful load is generally over 500 pounds and the takeoff and climb performance suffer.
All the Champs have wood spars, as do the Citabrias. The American Champion Explorer line is the first of the metal spar aircraft. Some have been converted to either ACA or Milman (sp?) metal spars. The seller will tell you if it has metal spars. You can take out an inspection cover to verify, as there'll be several in the bottom of the wing. There's nothing wrong with the wood spars, provided they're in airworthy condition. At 90hp and under, the inspection is a one-time thing unless you drag a wingtip or are subjecting the airframe to abuse - floats, skis, acro, etc.
There's a serial number range where the max gross goes to 1500 if the wide-stance gear are installed. The type certificate has that information; I think the number is in the 400s. Both the FC and the EC are eligible for the higher weight.
The EC can be converted to a 7GC with a Champion service bulletin. This is a 135hp, Lycoming O-290D2 engine. There are requirements for big wing tanks and such. Jerry M. can provide the info, I think (maybe for a nominal fee?).
If you want a Lycoming-powered ship, you may want to buy a 7ECA or GCAA instead. The older ones - 1960s - have the oleo gear but have the squared rudder/tail and rear windows. They also have a gross weight of 1650 pounds (but about the same useful load as the EC). These need an annual spar inspection unless they've been upgraded to metal spars.
Jon B.
