I started into an older 850 I had looked at for way too long. The previous owner told me it only grinded when he tried to put it in gear. I rebuilt the carb, then replaced the blown head gasket, runs great. But, even though the clutch is disengaging, the drive shaft will stay turning, not allowing you to go into gear, unless I start it in gear. Can the pilot bushings on these seize up and lock the flywheel to the drive shaft? If not, any ideas on what else may cause this. The clutch plate itself is definitely disengaging and separating by at least and 1/8th of an inch. I do see a shiny looking sleeve or shaft when I look into the gap. Thanks in advance.