I have never had problems with either light-duty or heavy-duty four foot mowers on by B7100. I have used an old Ford branded light weight one that I gave away a few years ago, a light weight Farm-Force, and a heavy duty, pro-model King Cutter. No problems with any of them. One thing I like about it when using a lightweight mower is that if I hit something that hangs the mower blades up, it will lug down the engine rather than breaking the sheer bolt. On my JD 3005, I can break a sheer bolt on the light weight farm force just by starting it up too fast.
On another topic, mowing an open field with the B7100 is bouncy and tedious, I much prefer the bigger, heavier, gear-transmission Deere. But around buildings and small lots the B7100 [with hydrostatic transmission] is my preference.
Mf