I am looking for a second mower. I found a 1999 John Deere F620 54" Z-TRAC for sale. It is about a 4 hour drive for me so I cant go take a look at it without making a day out of it. There are a few issues I was wondering about. Is thing a good option for a commercial mower? (this is the larger Z-TRAC with the 3rd single wheel in the back. The owner says that he took the deck off to paint it and when he put it back on, it does not cut even. He says that he did not remove any pullys or bearings, etc. He says that the back of the deck look higher than the front, and that when he cuts, it leaves a tall strip in the center. I am not familiar with this model and have never seen one. Is the some kind of adjustment that he is missing? Is this a true floating deck? What could cause this. Next issue, he says that the original motor (Kohler 20) has about 1100 hours on it. But it slung a rod and he rebuilt the motor. He said he put 2 new piston rods in, and a new head. And he says that there was minimal damage inside the piston. He says that since he rebuilt it, it has 5 hours on it, and it runs strong. Im not sure how much he knows about rebuilding motors but he says that it runs great now and that he would let me test it out. Is there anything I should be cautious about, or should the motor be ok? Mostly I need opinions on what could be wrong with this deck. He says that he will sell it for $2000, and he just cant figure out why it cuts uneven, I hope it is just a simple ajustment that he is missing. But I am not familiar with this model and it's deck. Opinions Please, Thanks in advance.