HI, I had a 610 which is the same machine with a 30 hp engine instead of the 25 the 600 had. There may be a plate in the center of the vertical plate behind your feet as you sit on the machine, this is where the serial # is and your Bobcat dealer can tell you the year. If it was just ignition problems the parts are available from the auto parts store or Bobcat. They had a mechanical spark advance in the lower part of the dist be sure to check it for free movement most are rusted up if not maintained. Like Ken said you can get parts for them at Bobcat. The wisconsin engine is a noisy engine naturally due to ball bearing mains but pretty durable if taken care of. You do hear of a lot of them with broken crankshafts. If you got it free and can save the engine without replacing it you have a great deal. If you replace the engine and maybe new tires and a few odd cylinder seals and things like that it still will be worth doing. Check what the better ones go for on e-bay. Plan on spending quite a bit of time on it, they are mechanical drive not hydro and adjusting the drive chains and clutches can take a while. Also check the forum here for back posts on m600 to give you a better idea of the machine.Bobcat stills supplies parts, many aftermarket are available to. There are a few guys with these loaders on this forum, I'm sure you will here from them.