Good Luck on those Kohler Courage motors. I hate em' personally.
Like IL ENGINE said, those top bolts work loose and hit the flywheel.
Been there done that deal. When you pull the flywheel and tighten
them down use some thread lock. When they get loose like that the
engine will usually, due to vibration or impact, put a lightning zigzag
type crack down the block and it's ready for the bone yard then!