Sounds like you're due for a seasonal tune-up...No?
How long ago since the carb was rebuilt? Looks like you should check into some new plugs, wires, cap/rotor, etc, etc..ya know..tune-up type stuff.
As far as the excessive fuel consumption, it sounds like a multitude of problems...tune-up, leaking carb, fouled plugs...
Hope this helps you out.
~Ty