Bad Boy MZ 54" ZTR mower with Kohler KT740 (Kohler 7000). I can't keep the PTO clutch installed. Have repeatedly replaced bolts and "dented washer" and a few seconds of run time on the deck and the bolt into the crankshaft falls out and drops the PTO clutch assembly in the yard... then jack it up, fight with the belts and do it all over again. Mower starts, drives and runs well... but this problem is going to get the whole thing scrapped. Help!!!