I just completely rebuilt the head on my 845 and I can't seem to get the clutch adjustment right. Can't seem to get it to disengage. 845 and 847 are identical other then the head from what I can see and what Marty at Wells Index said. The engage/disengage lever may be the issue but it sure looks like I assembled it right. I attached some photos and the diagram from the manual. Any input appreciated.