You realize that it's approx. 40 years old and some parts are near impossible to find, especially for the drive system? It's not hydrostatic but uses a 2 speed clutch set up as I understand it. They were a good machine in their day and may provide you with a lot of service but if you plan to do a lot of side work, you may want to look at a newer machine. The Wisconsin engines in them I think are VH4D's (30 HP)and would require an engine job every 1000 to 1500 hours according to a dealer who used to sell them. I think because of their location they were prone to overheating.
Sounds like a stuck float or some dirt got sucked in the carb when it ran out of gas.