I have an old Wheel Horse garden tractor. It has a belt to drive the mower blades, but it uses a transmission for the wheels. It was my understanding that the hydro system drove the blades and wheels. Do the older walk behinds use a belt for driving the wheels? How do you inspect an old engine on those mowers to make sure it's good to go.I say no. Get an older machine that has belt drive. Way cheaper to keep running. Keep a pair of belts on the truck. Can get the mower going at the customers house in no time. In comparison having to haul it down to a super busy mower shop during peak mowing season LOL. And spending thousands to get it repaired. Finally you get a call 8 months later, your mower is ready sir LOL.
Stay far away from hydros, their oils and hoses, leaks, pump failures and the like. $$$$
Look for an older belt drive JD, SCAG or Snapper Pro.
Make sure it doesn't smoke or use any oil. Ask the owner and roll the dice LOL. Look at the spark plug/s and inside the cylinder/s with the plug/s removed. Cheap USB inspection camera can help here. Other than that, dump the fuel tank, fresh fuel lines and filter. Adjust the valves and clean the cooling fins are a must on ALL mowers. Some fresh SAE30w and sharp blades.How do you inspect an old engine on those mowers to make sure it's good to go.