We have a Aqua Magic Style Plus in our 07 Contessa, The pedal started to push hard and the bowl door would snap open and closed.
I tried claening and lubing with silicone several times, finally depressing the pedal did nothing at all. I removed the unit and removed the water valve for access to the bowl door operating lever, Found the shaft part of the bowl valve was broken, no parts available at the time, This happened at the pre ralley in Moultrie, Ga. Thanks to the BAC president we did some brainstorming and decided to drill out both parts to 1/4 in, determined how to index the two parts to be positioned correctly when installed, reinstalled the bowl valve,, installed the lever from the outside, indexed to correct position,installed and tightened the bolt, Note: When reinstalling the bowl to the pedestal, just tighten the four bolts equally to a point that the bowl does not rock on the base,but no tighter, Even with the temporary fix, the bowl door has never worked so smoothly. I firmly believe the cause of the problem was that the bowl mounting nuts were tightened too tight by the installer as two were much tighter than they should have been. I've spoken to other owners who have toilets that do no operate smoothly and will be looking at the same issue if they don't do preventative care.