Bad day yesterday-first G18 stops running and then the 60 inch deck on my G20 blades starts and stops spinning. I noticed the grass was not being cut very well so I looked down and saw the blade spindle going fast, then slow, then fast, etc... I went to the barn and noticed the pto lever had no clearance at the front of the slot. I adjusted clearance to 3/4 inch and tried to mow-same problem. Two side notes-(1) tractor only has 265 hours on it,and (2) this happened once last year but after adjusting gap mower worked all last summer and this spring until now. I would suspect pto clutch but this would seem like a very early failure. I have plenty of room on the adjustment rod and may try to change gap both ways to see if there is a change.