I have a Toro recycler with a Tecumseh 6.5 hp engine that a friend of mine gave to me the other day. He told me that it ran good but suddenly would not start. I looked around and then found that the flywheel key was sheared so i got a new one and the mower runs good. It doesn't vibrate indicating a bent or loose crankshaft or connecting rod but if you push the lever down for the self propelled it doesn't move. The gears inside the wheels are fine and if you move the pulley the wheels do spin. I took the cover off where the belt is and had it running and when you push down the bar the belt doesn't move. I thought the belt was old so got a new one and it still doesn't work. I also tried adjusting the cable but it still does nothing... Any suggestions?