Any Zero-Turn Mower Experts?

Alright, just to finally wrap this thread up. I've been trying to diagnose the issue with this mower, and finally took it to an Exmark Dealer for them to check it out and pressure test the hydro pump. They stated the pump was weak, but couldn't guarantee the wheel motor wasn't shot either. They priced 1500 bucks just to get started. The pump alone was almost 700, not including any lines or if it was also a bad wheel motor. Mom asked them what they would do, and the guy told her there was no way he would put that kind of money into that mower. Another guy made an offer on it and she took it, so it's gone now. His buddy is an Exmark dealer in Kentucky, so they'll probably fix it or use it for parts.