Got a 61" Scag STHM, 3-wheel rider. I completely refurbished it for my own use. New motor, paint, belts, pulleys, bushings and seal kit for the hydro pump. Kept it all clean, put in the new seals and gaskets and now it does not pump. During the refurb, all the oil drained from the entire hydro system, motors, cooler, lines etc. I thought it needed to prime so I cracked open several different lines with the engine running, I got some low pressure oil spray from the line that goes to the oil filter. The pump gets hot within 2 minutes. I have ran it about 25 minutes total, with the wheels off the ground. The wheels just barley turn, but with no power. Help please! Could I STILL have air in the system? Is there a way to purge the pump? FYI: NEW 23 Kohler cost me $650! I get'em cheap all the time.