I agree with Grizz_Equip The 650H is generally a good, smooth 90-hp hydrostatic dozer. It has an electronic transmission controller and sensors, but it predates DPF, regeneration and DEF; emissions equipment is not the major concern. At 7,000 hours, measure the undercarriage, sample the hydrostat and final-drive oils, retrieve all stored codes, and work it long enough to get the powertrain completely hot. Test straight tracking, full-power turns and counter-rotation in both directions. Any weakness or unequal response when hot deserves pressure and case-drain testing before purchase. A worn undercarriage or hydrostatic system will matter far more than the hour-meter reading. Deere still provides a dedicated 650H owner-support page . The two manuals worth having are TM1743, Operation and Tests, and TM1744, Repair.