1. Does it have the hitch with the gearboxes that allow you to make tight turns without winding up the PTO shaft? Very helpful on the 12' header, not an option on the 15' header.

2. Did the owner change the cutterbed oil every year, and did he use the proper lube? Proper lube would be 80W90 or straight 90EP gear lube, NOT 85W140.

3. Look at the turtleshells on the discs -- if you see any welds, walk away. They're not supposed to have holes in the turtleshells or any other rotating part of the disc fixed by welding. Occasionally, in fields with squirrel/gopher mounds, you see the turtleshells get holes worn through in them. Just replace them whole.

4. Look at the drive line, from the tractor down into the cutterbed. Check all the gearboxes and bearings, make sure they have lube and the bearings are OK.

5. Look at the drive belts.

6. If you can get into the conditioner, try moving the conditioner roll ends to check the bearings. Those are sealed bearings and a right pain in the rump to change. Oh, and the bearings cost like about $80 each, last I looked, which was years ago.

Good mower-conditioners on the whole. They need their maintenance on a regular basis -- there is a lot of power being pushed through their drivetrain, sometimes concentrated into a single belt or gearbox along the way.