A very few carriers placard the overwing exits with their weight, although it's an awkward position to get into only to be surprised you have to swing half a hundredweight.
26kgs is a figure that comes to mind for the 737 - think it was Luxair, but can't exactly remember - it was a few years since I saw the placard.
Talking of Ryanair, they operate the 737 NG and the overwing exit swings up and out when operated - this strikes me as being much better than having to pull, twist, push and chuck in the classics and the minibuses.