Ok, maybe I am doing something dumb here- I am new to this machine, a Kubota B7200. I hooked up my bush hog, engaged the pto and let the clutch out- no prob mower works great- but when I go to disengage the pto, I push the clutch in, move the lever to the off position and rel the clutch the mower spins back up again- unless I shut the machine off and re-start it.... then it stays off... any ideas??