As the subject said I was running a 331 Bobcat mini doing a small job for my dad. The machine is a rental it is being shipped off some where so I thought I might aswell get some use out of it. The machine isn't brandnew it has 2500 hours on it it must be about a 2006 machine maybe older. I ran the machine for 1.5 hours working some material pulling the rocks out and spreading some of the fines. First of all what a piece of crap the machine is just as tippy as the 325 I ran 6 years ago. The material I was working with is pretty coarse the boulders are 100-200lbs. I grabbed one of the largest boulders I say 200lbs the machine darn near rolled over with the boom stretched out a little ways. The controls are not smooth no matter how hard you tried to feather the sticks the thing was jumpy. I had it throttled right up I never run a machine at low rpms. Even with the blade down the machine flopped all over like a frigging carnival ride. I couldn't get a decent grade using the clean up bucket. The thing had no digging power you curl the bucket and the machine powered out. Then do something else no power than all of a sudden it over powers. I have ran a old EX-150 Hitachi with over 13,000 hours that performed better than the Bobcat mini. I did the best I could and dad will have to do the rest by hand. I got the big rocks out of the material. I really hope who ever is going to be using the machine isn't plan on doing fine work they will never do it. Ya its a rental machine and its been ragged on. It doesn't matter if the Bobcat Mini is larger the machine still is tippy and no power. I know I won't be renting that machine for any jobs its a horrible thing to run.