I have a 1953 JD 50 with a separate clutch for the pto. If I turn the small handle by the shifter to the left to engage the pto and lift the clutch handle to the right of the seat the engine bogs down and no pto action. The clutch handle doesn't snap into postion and wouldn't stay up by itself. Also if I disengage the pto and attach a driveshaft to the pto shaft ( with the engine shut off) I can use use a prybar in the u-joint and turn the pto shaft - but it is hard to turn. Where do I start?